The Battle of Antietam (), or Battle of Sharpsburg particularly in the

Southern United States The Southern United States (sometimes Dixie, also referred to as the Southern States, the American South, the Southland, or simply the South) is a geographic and cultural region of the United States of America. It is between the Atlantic Ocean ...

, was a battle of the

American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by other names) was a civil war in the United States. It was fought between the Union ("the North") and the Confederacy ("the South"), the latter formed by states th ...

fought on September 17, 1862, between Confederate Gen. Robert E. Lee's

Army of Northern Virginia The Army of Northern Virginia was the primary military force of the Confederate States of America in the Eastern Theater of the American Civil War. It was also the primary command structure of the Department of Northern Virginia. It was most oft ...

and Union Gen.

George B. McClellan George Brinton McClellan (December 3, 1826 – October 29, 1885) was an American soldier, Civil War Union general, civil engineer, railroad executive, and politician who served as the 24th governor of New Jersey. A graduate of West Point, McCl ...

Army of the Potomac The Army of the Potomac was the principal Union Army in the Eastern Theater of the American Civil War. It was created in July 1861 shortly after the First Battle of Bull Run and was disbanded in June 1865 following the surrender of the Confedera ...

near

Sharpsburg, Maryland Sharpsburg is a town in Washington County, Maryland. The town is approximately south of Hagerstown. Its population was 705 at the 2010 census. During the American Civil War, the Battle of Antietam, sometimes referred to as the Battle of Sharpsb ...

and

Antietam Creek Antietam Creek () is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed August 15, 2011 tributary of the Potomac River located in south central Pennsylvania and western Maryland in the ...

. Part of the Maryland Campaign, it was the first

field army A field army (or numbered army or simply army) is a military formation in many armed forces, composed of two or more corps and may be subordinate to an army group. Likewise, air armies are equivalent formation within some air forces, and with ...

–level engagement in the Eastern Theater of the American Civil War to take place on Union soil. It remains the bloodiest day in American history, with a combined tally of 22,717 dead, wounded, or missing. Although the Union army suffered heavier casualties than the Confederates, the battle was a major turning point in the Union's favor. After pursuing

Confederate Confederacy or confederate may refer to: States or communities * Confederate state or confederation, a union of sovereign groups or communities * Confederate States of America, a confederation of secessionist American states that existed between 1 ...

Gen. Robert E. Lee into

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

Maj. Gen. Major general (abbreviated MG, maj. gen. and similar) is a military rank used in many countries. It is derived from the older rank of sergeant major general. The disappearance of the "sergeant" in the title explains the apparent confusion of a ...

George B. McClellan of the

Union Army During the American Civil War, the Union Army, also known as the Federal Army and the Northern Army, referring to the United States Army, was the land force that fought to preserve the Union (American Civil War), Union of the collective U.S. st ...

launched attacks against Lee's army who were in defensive positions behind Antietam Creek. At dawn on September 17, Maj. Gen.

Joseph Hooker Joseph Hooker (November 13, 1814 – October 31, 1879) was an American Civil War general for the Union, chiefly remembered for his decisive defeat by Confederate General Robert E. Lee at the Battle of Chancellorsville in 1863. Hooker had serv ...

's corps mounted a powerful assault on Lee's left flank. Attacks and counterattacks swept across Miller's Cornfield, and fighting swirled around the Dunker Church. Union assaults against the Sunken Road eventually pierced the Confederate center, but the Federal advantage was not followed up. In the afternoon, Union Maj. Gen.

Ambrose Burnside Ambrose Everett Burnside (May 23, 1824 – September 13, 1881) was an American army officer and politician who became a senior Union general in the Civil War and three times Governor of Rhode Island, as well as being a successful inventor ...

's corps entered the action, capturing a stone bridge over Antietam Creek and advancing against the Confederate right. At a crucial moment, Confederate Maj. Gen. A. P. Hill's division arrived from

Harpers Ferry Harpers Ferry is a historic town in Jefferson County, West Virginia. It is located in the lower Shenandoah Valley. The population was 285 at the 2020 census. Situated at the confluence of the Potomac and Shenandoah rivers, where the U.S. stat ...

and launched a surprise counterattack, driving back Burnside and ending the battle. Although outnumbered two-to-one, Lee committed his entire force, while McClellan sent in less than three-quarters of his army, enabling Lee to fight the Federals to a standstill. During the night, both armies consolidated their lines. In spite of crippling casualties, Lee continued to skirmish with McClellan throughout September 18, while removing his battered army south of the

Potomac River The Potomac River () drains the Mid-Atlantic United States, flowing from the Potomac Highlands into Chesapeake Bay. It is long,U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map. Retrieved Augus ...

. McClellan successfully turned Lee's invasion back, making the battle a Union victory, but President

Abraham Lincoln Abraham Lincoln ( ; February 12, 1809 – April 15, 1865) was an American lawyer, politician, and statesman who served as the 16th president of the United States from 1861 until his assassination in 1865. Lincoln led the nation thro ...

, unhappy with McClellan's general pattern of overcaution and his failure to pursue the retreating Lee, relieved McClellan of command in November. From a

tactical Tactic(s) or Tactical may refer to: * Tactic (method), a conceptual action implemented as one or more specific tasks ** Military tactics, the disposition and maneuver of units on a particular sea or battlefield ** Chess tactics ** Political tacti ...

standpoint, the battle was somewhat inconclusive; the Union army successfully repelled the Confederate invasion but suffered heavier casualties and failed to defeat Lee's army outright. However, it was a significant turning point in the war in favor of the Union due in large part to its political ramifications: the battle's result gave Lincoln the political confidence to issue the

Emancipation Proclamation The Emancipation Proclamation, officially Proclamation 95, was a presidential proclamation and executive order issued by United States President Abraham Lincoln on January 1, 1863, during the Civil War. The Proclamation changed the legal sta ...

, declaring all those held as slaves within enemy territory free. This effectively discouraged the British and French governments from recognizing the Confederacy, as neither power wished to give the appearance of supporting slavery.

Background

Robert E. Lee's

—about 55,000 men—entered the state of

on September 3, following their victory at

Second Bull Run The Second Battle of Bull Run or Battle of Second Manassas was fought August 28–30, 1862, in Prince William County, Virginia, as part of the American Civil War. It was the culmination of the Northern Virginia Campaign waged by Confederat ...

on August 30. Emboldened by success, the Confederate leadership intended to take the war into enemy territory. Lee's invasion of Maryland was intended to run simultaneously with an invasion of Kentucky by the armies of

Braxton Bragg Braxton Bragg (March 22, 1817 – September 27, 1876) was an American army officer during the Second Seminole War and Mexican–American War and Confederate general in the Confederate Army during the American Civil War, serving in the Weste ...

and

Edmund Kirby Smith General Edmund Kirby Smith (May 16, 1824March 28, 1893) was a senior officer of the Confederate States Army who commanded the Trans-Mississippi Department (comprising Arkansas, Missouri, Texas, western Louisiana, Arizona Territory and the Indi ...

. It was also necessary for logistical reasons, as northern Virginia's farms had been stripped bare of food. Based on events such as the Baltimore riots in the spring of 1861 and the fact that President Lincoln had to pass through the city in disguise en route to his inauguration, Confederate leaders assumed that Maryland would welcome the Confederate forces warmly. They sang the tune "

Maryland, My Maryland "Maryland, My Maryland" was the state song of the U.S. state of Maryland from 1939 until 2021. The song is set to the melody of "Lauriger Horatius" — the same tune "O Tannenbaum" was taken from. The lyrics are from a nine-stanza poem written by ...

!" as they marched, but by the fall of 1862 pro-Union sentiment was winning out, especially in the western parts of the state. Civilians generally hid inside their houses as Lee's army passed through their towns, or watched in cold silence, while the

was cheered and encouraged. Some Confederate politicians, including

President President most commonly refers to: *President (corporate title) *President (education), a leader of a college or university *President (government title) President may also refer to: Automobiles * Nissan President, a 1966–2010 Japanese ful ...

Jefferson Davis Jefferson F. Davis (June 3, 1808December 6, 1889) was an American politician who served as the president of the Confederate States from 1861 to 1865. He represented Mississippi in the United States Senate and the House of Representatives as a ...

, believed that the prospect of foreign recognition would increase if the Confederacy won a military victory on Union soil; such a victory might gain recognition and financial support from the United Kingdom and France, although there is no evidence that Lee thought the Confederacy should base its military plans on this possibility. While McClellan's 87,000-man

was moving to intercept Lee, two Union soldiers ( Cpl. Barton W. Mitchell and First Sergeant John M. Bloss of the 27th Indiana Volunteer Infantry) discovered a mislaid copy of Lee's detailed battle plans—

Special Order 191 Special Order 191 (series 1862), also known as the "Lost Dispatch" and the "Lost Order", was a general movement order issued by Confederate Army General Robert E. Lee on about September 9, 1862, during the Maryland Campaign of the American Civi ...

—wrapped around three cigars. The order indicated that Lee had divided his army and dispersed portions geographically (to

Harpers Ferry, West Virginia Harpers Ferry is a historic town in Jefferson County, West Virginia. It is located in the lower Shenandoah Valley. The population was 285 at the 2020 census. Situated at the confluence of the Potomac and Shenandoah rivers, where the U.S. stat ...

, and

Hagerstown, Maryland Hagerstown is a city in Washington County, Maryland, United States and the county seat of Washington County. The population of Hagerstown city proper at the 2020 census was 43,527, and the population of the Hagerstown metropolitan area (exten ...

), thus making each subject to isolation and defeat if McClellan could move quickly enough. McClellan waited about 18 hours before deciding to take advantage of this intelligence and reposition his forces, thus squandering an opportunity to defeat Lee decisively. There were two significant engagements in the Maryland campaign prior to the major battle of Antietam: Maj. Gen. Thomas J. "Stonewall" Jackson's capture of

and McClellan's assault through the

Blue Ridge Mountains The Blue Ridge Mountains are a physiographic province of the larger Appalachian Mountains range. The mountain range is located in the Eastern United States, and extends 550 miles southwest from southern Pennsylvania through Maryland, West Virgin ...

in the

Battle of South Mountain The Battle of South Mountain—known in several early Southern accounts as the Battle of Boonsboro Gap—was fought on September 14, 1862, as part of the Maryland campaign of the American Civil War. Three pitched battles were fought for posses ...

. The former was significant because a large portion of Lee's army was absent from the start of the battle of Antietam, attending to the surrender of the Union garrison; the latter because stout Confederate defenses at two passes through the mountains delayed McClellan's advance enough for Lee to concentrate the remainder of his army at Sharpsburg.

Opposing forces

Union

Maj. Gen. George B. McClellan's

, bolstered by units absorbed from John Pope's

Army of Virginia The Army of Virginia was organized as a major unit of the Union Army and operated briefly and unsuccessfully in 1862 in the American Civil War. It should not be confused with its principal opponent, the Confederate Army of ''Northern'' Virginia ...

, included six infantry corps. The

I Corps I Corps, 1st Corps, or First Corps may refer to: France * 1st Army Corps (France) * I Cavalry Corps (Grande Armée), a cavalry unit of the Imperial French Army during the Napoleonic Wars * I Corps (Grande Armée), a unit of the Imperial French A ...

, under Maj. Gen.

, consisted of the divisions of: * Brig. Gen.

Abner Doubleday Abner Doubleday (June 26, 1819 – January 26, 1893) was a career United States Army officer and Union major general in the American Civil War. He fired the first shot in defense of Fort Sumter, the opening battle of the war, and had a pi ...

(brigades of Col.

Walter Phelps Walter P. Phelps Jr. (Oct 29, 1832–February 20, 1878) was an officer in the Union Army throughout the American Civil War, serving as commanding officer of the Eastern Iron Brigade. Biography Phelps was born in on October 29, 1832 Hartford, Conn ...

, Brig. Gens.

Marsena R. Patrick Marsena Rudolph Patrick (March 15, 1811 – July 27, 1888) was a college president and an officer in the United States Army, serving as a general in the Union Army, Union volunteer forces during the American Civil War. He was the provost marshal fo ...

and

John Gibbon John Gibbon (April 20, 1827 – February 6, 1896) was a career United States Army officer who fought in the American Civil War and the Indian Wars. Early life Gibbon was born in the Holmesburg section of Philadelphia, Pennsylvania, the fourt ...

, and

Lt. Col. Lieutenant colonel ( , ) is a rank of commissioned officers in the armies, most marine forces and some air forces of the world, above a major and below a colonel. Several police forces in the United States use the rank of lieutenant colonel. ...

J. William Hofmann). * Brig. Gen.

James B. Ricketts James Brewerton Ricketts (June 21, 1817 – September 22, 1887) was a career officer in the United States Army, serving as a Union Army general during the Civil War. At First Bull Run, he was wounded and captured, but later exchanged. He fought a ...

(brigades of Brig. Gen.

Abram Duryée Abram Duryée (; April 29, 1815 – September 27, 1890) was a Union Army general during the American Civil War, the commander of one of the most famous Zouave regiments, the 5th New York Volunteer Infantry. After the war he was New York Cit ...

, Col. William H. Christian, and Brig. Gen. George L. Hartsuff). * Brig. Gen.

George G. Meade George Gordon Meade (December 31, 1815 – November 6, 1872) was a United States Army officer and civil engineer best known for decisively defeating Confederate General Robert E. Lee at the Battle of Gettysburg in the American Civil War. H ...

(brigades of Brig. Gen.

Truman Seymour Truman Seymour (September 24, 1824 – October 30, 1891) was a career soldier and an accomplished painter. He served in the Union Army during the American Civil War, rising to the rank of major general. He was present at the Battle of Fort S ...

, Col. Albert Magilton and Lt. Col. Robert Anderson). The II Corps, under Maj. Gen. Edwin V. Sumner, consisted of the divisions of: * Maj. Gen.

Israel B. Richardson Israel Bush Richardson (December 26, 1815 – November 3, 1862) was a United States Army officer during the Mexican–American War and American Civil War, where he was a major general in the Union Army. Nicknamed "Fighting Dick" for his prowess on ...

(brigades of Brig. Gen. John C. Caldwell, Brig. Gen.

Thomas F. Meagher Thomas Francis Meagher (; 3 August 18231 July 1867) was an Irish nationalism, Irish nationalist and leader of the Young Irelanders in the Young Irelander Rebellion of 1848, Rebellion of 1848. After being convicted of sedition, he was first sent ...

, and Col.

John R. Brooke John Rutter Brooke (July 21, 1838 – September 5, 1926) was one of the last surviving Union generals of the American Civil War when he died at the age of 88. Early life Brooke was born in Pottstown, Pennsylvania, and was educated in nearby Coll ...

). * Maj. Gen.

John Sedgwick John Sedgwick (September 13, 1813 – May 9, 1864) was a military officer and Union Army general during the American Civil War. He was wounded three times at the Battle of Antietam while leading his division in an unsuccessful assault against C ...

(brigades of Brig. Gens.

Willis A. Gorman Willis Arnold Gorman (January 12, 1816 – May 20, 1876) was an American lawyer, soldier, politician, and a general in the Union Army during the American Civil War. Biography Gorman was born near Flemingsburg, Kentucky. He was the only child of D ...

, Oliver O. Howard, and Napoleon J.T. Dana). * Brig. Gen. William H. French (brigades of Brig. Gen.

Nathan Kimball Nathan Kimball (November 22, 1822 – January 21, 1898) was a physician, politician, postmaster, and military officer, serving as a general in the Union army during the American Civil War. He was the first statewide commander of the Grand Arm ...

, Col.

Dwight Morris Timothy Dwight Morris, commonly known as simply Dwight Morris was an American colonel who commanded the 14th Connecticut Infantry Regiment during the American Civil War as well as commanding the 2nd Brigade of the 2nd Corps during the Battle of A ...

, and Brig. Gen.

Max Weber Maximilian Karl Emil Weber (; ; 21 April 186414 June 1920) was a German sociologist, historian, jurist and political economist, who is regarded as among the most important theorists of the development of modern Western society. His ideas profo ...

). The

V Corps 5th Corps, Fifth Corps, or V Corps may refer to: France * 5th Army Corps (France) * V Cavalry Corps (Grande Armée), a cavalry unit of the Imperial French Army during the Napoleonic Wars * V Corps (Grande Armée), a unit of the Imperial French Ar ...

, under Maj. Gen.

Fitz John Porter Fitz John Porter (August 31, 1822 – May 21, 1901) (sometimes written FitzJohn Porter or Fitz-John Porter) was a career United States Army officer and a Union general during the American Civil War. He is most known for his performance at the Sec ...

, consisted of the divisions of: * Maj. Gen. George W. Morell (brigades of Col. James Barnes, Brig. Gen.

Charles Griffin Charles Griffin (December 18, 1825 – September 15, 1867) was a career officer in the United States Army and a Union general in the American Civil War. He rose to command a corps in the Army of the Potomac and fought in many of the key campaign ...

, and Col.

T.B.W. Stockton Thomas Baylis Whitmarsh Stockton, commonly known as T.B.W. Stockton was an American Colonel and Engineer who commanded the 16th Michigan Infantry Regiment during the American Civil War as well as being a major contributor to the infrastructure o ...

). * Brig. Gen.

George Sykes George Sykes (October 9, 1822 – February 8, 1880) was a career United States Army officer and a Union General during the American Civil War. He graduated from the United States Military Academy in 1842, and served in numerous conflicts, ...

(brigades of Lt. Col.

Robert C. Buchanan Robert Christie Buchanan (March 1, 1811 – November 29, 1878) was an American military officer who served in the Mexican–American War and then was a Colonel (United States), colonel in the Union Army during the American Civil War. In 1866, ...

Maj. Maj may refer to: * Major, a rank of commissioned officer in many military forces * ''Máj'', a romantic Czech poem by Karel Hynek Mácha * ''Máj'' (literary almanac), a Czech literary almanac published in 1858 * Marshall Islands International Ai ...

Charles S. Lovell Charles Swain Lovell was an American military officer and Brevet Brigadier General who commanded a brigade during several major battles of the American Civil War. Biography Lovell was born on February 13, 1811, in Hull, Massachusetts. He would e ...

, and Col.

Gouverneur K. Warren Gouverneur Kemble Warren (January 8, 1830 – August 8, 1882) was an American civil engineer and Union Army general during the American Civil War. He is best remembered for arranging the last-minute defense of Little Round Top during the Battle ...

). * Brig. Gen. Andrew A. Humphreys (brigades of Brig. Gen.

Erastus B. Tyler Erastus Bernard Tyler (April 24, 1822 – January 9, 1891) was an American businessman, merchant, and soldier. He was a general in the Union Army during the American Civil War and fought in many of the early battles in the Eastern Theater before ...

and Col. Peter H. Allabach). The

VI Corps 6 Corps, 6th Corps, Sixth Corps, or VI Corps may refer to: France * VI Cavalry Corps (Grande Armée), a cavalry formation of the Imperial French army during the Napoleonic Wars * VI Corps (Grande Armée), a formation of the Imperial French army du ...

, under Maj. Gen. William B. Franklin, consisted of the divisions of: * Maj. Gen. Henry W. Slocum (brigades of Col. Alfred T.A. Torbert, Col.

Joseph J. Bartlett Joseph Jackson Bartlett (November 21, 1834 – January 14, 1893) was a New York attorney, brigadier general in the Union Army during the American Civil War, and postbellum international diplomat and pensions administrator for the United States ...

, and Brig. Gen.

John Newton John Newton (; – 21 December 1807) was an English evangelical Anglican cleric and slavery abolitionist. He had previously been a captain of slave ships and an investor in the slave trade. He served as a sailor in the Royal Navy (after forc ...

). * Maj. Gen. William F. "Baldy" Smith (brigades of Brig. Gens.

Winfield S. Hancock Winfield Scott Hancock (February 14, 1824 – February 9, 1886) was a United States Army officer and the Democratic nominee for President of the United States in 1880. He served with distinction in the Army for four decades, including service ...

and William T. H. Brooks and Col. William H. Irwin). * A division from the IV Corps under Maj. Gen. Darius N. Couch (brigades of Brig. Gens.

Charles Devens, Jr. Charles Devens Jr. (April 4, 1820 – January 7, 1891) was an American lawyer, jurist and statesman. He also served as a general in the Union Army during the American Civil War. Early life and career Born in Charlestown, Massachusetts, Devens gr ...

, Albion P. Howe, and John Cochran). The

IX Corps 9 Corps, 9th Corps, Ninth Corps, or IX Corps may refer to: France * 9th Army Corps (France) * IX Corps (Grande Armée), a unit of the Imperial French Army during the Napoleonic Wars Germany * IX Corps (German Empire), a unit of the Imperial Germ ...

, under Maj. Gen.

Ambrose E. Burnside Ambrose Everett Burnside (May 23, 1824 – September 13, 1881) was an American army officer and politician who became a senior Union general in the Civil War and three times Governor of Rhode Island, as well as being a successful inventor ...

(Brig. Gen.

Jacob D. Cox Jacob Dolson Cox, Jr. (October 27, 1828August 4, 1900), was a statesman, lawyer, Union Army general during the American Civil War, Republican politician from Ohio, Liberal Republican Party founder, educator, author, and recognized microbiologist ...

exercised operational command during the battle), consisted of the divisions of: * Brig. Gen.

Orlando B. Willcox Orlando Bolivar Willcox (April 16, 1823 – May 11, 1907) was an American soldier who served as a general in the Union Army during the American Civil War. Early life Willcox was born in Detroit, Michigan. He entered the United States Military Ac ...

(brigades of Cols. Benjamin C. Christ and Thomas Welsh). * Brig. Gen. Samuel D. Sturgis (brigades of Brig. Gens. James Nagle and

Edward Ferrero Edward Ferrero (January 18, 1831 – December 11, 1899) was one of the leading dance instructors, choreographers, and ballroom operators in the United States. He also served as a Union Army general in the American Civil War, being most remembered f ...

). * Brig. Gen.

Isaac P. Rodman Isaac Peace Rodman (August 18, 1822 – September 30, 1862) was a Rhode Island banker, politician, and a Union Army Brigadier general (United States), brigadier general in the American Civil War, who became mortally wounded at the Battle of ...

(brigades of Cols. Harrison S. Fairchild and Edward Harland). *

Kanawha Division The Kanawha Division was a Union Army division which could trace its origins back to a brigade originally commanded by Jacob D. Cox. This division served in western Virginia and Maryland and was at times led by such famous personalities as George ...

, under Col. Eliakim P. Scammon (brigades of Cols.

Hugh Ewing Hugh Boyle Ewing (October 31, 1826 – June 30, 1905) was a diplomat, author, attorney, and Union Army general during the American Civil War. He was a member of the prestigious Ewing family, son of Thomas Ewing, the eldest brother of Thomas ...

and

George Crook George R. Crook (September 8, 1828 – March 21, 1890) was a career United States Army officer, most noted for his distinguished service during the American Civil War and the Indian Wars. During the 1880s, the Apache nicknamed Crook ''Nantan ...

). The

XII Corps 12th Corps, Twelfth Corps, or XII Corps may refer to: * 12th Army Corps (France) * XII Corps (Grande Armée), a corps of the Imperial French Army during the Napoleonic Wars * XII (1st Royal Saxon) Corps, a unit of the Imperial German Army * XII ...

, under Maj. Gen.

Joseph K. Mansfield Joseph King Fenno Mansfield (December 22, 1803 – September 18, 1862) was a career United States Army officer, civil engineer, and a Union general in the American Civil War, mortally wounded at the Battle of Antietam. Early life Mansfield was ...

, consisted of the divisions of: * Brig. Gen.

Alpheus S. Williams Alpheus Starkey Williams (September 20, 1810 – December 21, 1878) was a lawyer, judge, journalist, U.S. Congressman, and a Union Army, Union general in the American Civil War. Early life Williams was born in Deep River, Connecticut. He gradua ...

(brigades of Brig. Gens.

Samuel W. Crawford Samuel Wylie Crawford (November 8, 1829 – November 3, 1892) was a United States Army surgeon and a Union general in the American Civil War. He served as a surgeon at Fort Sumter, South Carolina during the confederate bombardment in 1861. ...

and George H. Gordon). * Brig. Gen. George S. Greene (brigades of Lt. Col.

Hector Tyndale Hector Tyndale (a.k.a. George Hector Tyndale) was a Union general during the American Civil War rising to the rank of Brevet Major General of Volunteers. He notably led brigades at the battles of Antietam and Wauhatchie. Apart from the war Tynda ...

, Col. Henry J. Stainrook, and Col. William B. Goodrich). The Cavalry Division of Brig. Gen.

Alfred Pleasonton Alfred Pleasonton (June 7, 1824 – February 17, 1897) was a United States Army officer and major general of volunteers in the Union cavalry during the American Civil War. He commanded the Cavalry Corps of the Army of the Potomac during the Gett ...

consisted of the brigades of Maj. Charles J. Whiting and Cols. John F. Farnsworth, Richard H. Rush, Andrew T. McReynolds, and

Benjamin F. Davis Benjamin Franklin "Grimes" Davis (October, 1831 – June 9, 1863) was an American military Officer (armed forces), officer who served in Indian Wars, Indian wars, and then led Union Army, Union Cavalry in the American Civil War, cavalry in ...

Confederate

General Lee's

was organized into two large infantry wings. Maj. Gen. James Longstreet's Right Wing or Command consisted of the following divisions: * Maj. Gen.

Lafayette McLaws Lafayette McLaws ( ; January 15, 1821 – July 24, 1897) was a United States Army officer and a Confederate general in the American Civil War. He served at Antietam and Fredericksburg, where Robert E. Lee praised his defense of Marye's Heights, ...

(brigades of Brig. Gens.

Joseph B. Kershaw Joseph Brevard Kershaw (January 5, 1822 – April 13, 1894) was a prominent South Carolina planter and slaveholder. He was also a lawyer, judge, and a Confederate general in the American Civil War. Early life Kershaw was born on January 5, 182 ...

Howell Cobb Howell Cobb (September 7, 1815 – October 9, 1868) was an American and later Confederate political figure. A southern Democrat, Cobb was a five-term member of the United States House of Representatives and the speaker of the House from 184 ...

Paul J. Semmes Paul Jones Semmes (June 4, 1815 – July 10, 1863) was a banker, businessman, and a Confederate brigadier general in the American Civil War, mortally wounded at the Battle of Gettysburg. Early life Semmes was born at Montford's Plantation in ...

, and

William Barksdale William Barksdale (August 21, 1821 – July 3, 1863) was a lawyer, newspaper editor, US Representative, and Confederate general in the American Civil War. A staunch secessionist, he was mortally wounded during the Battle of Gettysburg while he ...

). * Maj. Gen.

Richard H. Anderson Richard Anderson (1926–2017) was an American actor. Richard, Rich, Richie, or Dick Anderson may also refer to: Arts and entertainment * Richard Dean Anderson (born 1950), American actor * Richard L. Anderson (sound effects editor) (1977–2013) ...

(brigades of Cols. Alfred Cumming, W. A. Parham, and

Carnot Posey Carnot Posey (August 5, 1818 – November 13, 1863) was a Mississippi planter and lawyer, and a Confederate general in the American Civil War. He was mortally wounded at the Battle of Bristoe Station. He was transported for care to the Univers ...

, and Brig. Gens.

Lewis Armistead Lewis Addison Armistead (February 18, 1817 – July 5, 1863) was a career United States Army officer who became a brigadier general in the Confederate States Army during the American Civil War. On July 3, 1863, as part of Pickett's Charge during ...

Roger A. Pryor Roger Atkinson Pryor (July 19, 1828 – March 14, 1919) was a Virginian newspaper editor and politician who became known for his fiery oratory in favor of secession; he was elected both to national and Confederate office, and served as a gen ...

, and

Ambrose R. Wright Ambrose Ransom "Rans" Wright (April 26, 1826 – December 21, 1872) was a lawyer, Georgia politician, and Confederate general in the American Civil War. Early life Wright, known by the nickname "Rans", was born in Louisville, Georgia. He rea ...

). * Brig. Gen. David R. Jones (brigades of Brig. Gens. Robert A. Toombs,

Thomas F. Drayton Thomas Fenwick Drayton (August 24, 1809 – February 18, 1891) was a planter, politician, railroad president, slave owner and military officer from Charleston, South Carolina. He served in the United States Army and then as a brigadier gene ...

, Richard B. Garnett,

James L. Kemper James Lawson Kemper (June 11, 1823 – April 7, 1895) was a lawyer, a Confederate general in the American Civil War, and the 37th Governor of Virginia. He was the youngest brigade commander and only non-professional military officer in the div ...

, and Cols.

Joseph A. Walker Joseph Albert Walker (February 20, 1921 – June 8, 1966) (Capt, USAF) was an American World War II pilot, experimental physicist, NASA test pilot, and astronaut who was the first person to fly an airplane to space. He was one of twelve pilots ...

and George T. Anderson). * Brig. Gen. John G. Walker (brigades of Col. Van H. Manning and Brig. Gen. Robert Ransom, Jr.). * Brig. Gen.

John Bell Hood John Bell Hood (June 1 or June 29, 1831 – August 30, 1879) was a Confederate general during the American Civil War. Although brave, Hood's impetuosity led to high losses among his troops as he moved up in rank. Bruce Catton wrote that "the dec ...

(brigades of Cols. William T. Wofford and Evander M. Law). * Independent brigade under Brig. Gen. Nathan G. "Shanks" Evans. Maj. Gen. Thomas J. "Stonewall" Jackson's Left Wing or Command consisted of the following divisions: * Brig. Gen.

Alexander R. Lawton Alexander Robert Lawton (November 4, 1818 – July 2, 1896) was a lawyer, politician, diplomat, and brigadier general in the Confederate States Army during the American Civil War. Early life Lawton was born in the Beaufort District of South ...

(brigades of Col.

Marcellus Douglass Colonel Marcellus Douglass was a Confederate Army officer and commander of the 13th Georgia Infantry Regiment during the American Civil War. Douglass was born in Thomaston, Georgia, October 5, 1830. After graduation from the University of Georgia, ...

, Brig. Gen. Jubal A. Early, Col.

James A. Walker James Alexander Walker (August 27, 1832 – October 21, 1901) was a Virginia lawyer, politician, and Confederate general during the American Civil War, later serving as a United States Congressman for two terms. He earned the nickname "Ston ...

, and Brig. Gen.

Harry T. Hays Harry Thompson Hays (April 14, 1820 – August 21, 1876) was an American Army officer serving in the Mexican–American War and a general who served in the Confederate Army during the American Civil War. Known as the "Louisiana Tigers," his brigad ...

). * Maj. Gen.

A.P. Hill Ambrose Powell Hill Jr. (November 9, 1825April 2, 1865) was a Confederate general who was killed in the American Civil War. He is usually referred to as A. P. Hill to differentiate him from another, unrelated Confederate general, Daniel Harvey H ...

(the Light Division—brigades of Brig. Gens.

Lawrence O'Bryan Branch Lawrence O'Bryan Branch (November 28, 1820 – September 17, 1862) was a North Carolina representative in the U.S. Congress and a Confederate brigadier general in the American Civil War, killed at the Battle of Antietam. Early life and car ...

Maxcy Gregg Maxcy Gregg (August 1, 1814 – December 15, 1862) was a lawyer, soldier in the United States Army during the Mexican–American War, and a Confederate brigadier general during the American Civil War who was mortally wounded at the Battle of ...

James J. Archer James Jay Archer (December 19, 1817 – October 24, 1864) was a lawyer and an officer in the United States Army during the Mexican–American War. He later served as a brigadier general in the Confederate States Army (CSA) during the American Ci ...

, and

William Dorsey Pender William Dorsey Pender (February 6, 1834 – July 18, 1863) was a general in the Confederacy in the American Civil War serving as a brigade and divisional commander. Promoted to brigadier on the battlefield at Seven Pines by Confederate President ...

, and Cols. John M. Brockenbrough and

Edward L. Thomas Edward Lloyd Thomas (March 23, 1825 – March 8, 1898) was a Confederate States Army, Confederate Brigadier General (CSA), brigadier general of infantry during the American Civil War from the state of Georgia (U.S. state), Georgia. He was colonel ...

). * Brig. Gen. John R. Jones (brigades of Cols. A.J. Grigsby, E. T. H. Warren, Bradley T. Johnson, and Brig. Gen. William E. Starke). * Maj. Gen. D.H. Hill (brigades of Brig. Gens. Roswell S. Ripley,

Robert E. Rodes Robert Emmett (or Emmet) Rodes (March 29, 1829 – September 19, 1864) was a Confederate general in the American Civil War, and the first of Robert E. Lee's divisional commanders not trained at West Point. His division led Stonewall Jackso ...

, Samuel Garland, Jr., George B. Anderson, and Col.

Alfred H. Colquitt Alfred Holt Colquitt (April 20, 1824March 26, 1894) was an American lawyer, preacher, soldier, and politician. Elected as the List of Governors of Georgia, 49th Governor of Georgia (1877–1882), he was one of numerous Democrats elected to offi ...

). The remaining units were the

Cavalry Division Historically, cavalry (from the French word ''cavalerie'', itself derived from "cheval" meaning "horse") are soldiers or warriors who Horses in warfare, fight mounted on horseback. Cavalry were the most mobile of the combat arms, operating a ...

, under Maj. Gen. J. E. B. Stuart, and the reserve artillery, commanded by Brig. Gen.

William N. Pendleton William Nelson Pendleton (December 26, 1809 – January 15, 1883) was an American teacher, Episcopal priest, and soldier. He served as a Confederate general during the American Civil War, noted for his position as Gen. Robert E. Lee's chief ...

. Jackson's left wing was organized with artillery attached to each division, in contrast to Longstreet's right wing, which reserved its artillery at the corps level.

Prelude to battle

Disposition of armies

US ARMY MARYLAND CAMPAIGN MAP 4 (ANTIETAM)

Near the town of Sharpsburg, Lee deployed his available forces behind Antietam Creek along a low ridge, starting on September 15. While it was an effective defensive position, it was not an impregnable one. The terrain provided excellent cover for infantrymen, with rail and stone fences, outcroppings of

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

, little hollows and swales. The creek to their front was only a minor barrier, ranging from 60 to 100 feet (18–30 m) in width, and was fordable in places and crossed by three stone bridges each a mile (1.5 km) apart. It was also