Military history of the United States

This article needs to be updated. The reason given is: Domestic policy of the second Donald Trump administration. Please help update this article to reflect recent events or newly available information. (June 2025) The Battle of Gettysburg, the deadliest battle in both the American Civil War and all of American military history with over 50,000 combined Union and Confederate casualties, fought over three days between July 1 and July 3, 1863, in and around Gettysburg, Pennsylvania, depicted in an 1887 portrait by Thure de Thulstrup This article is part of a series on theHistory of the United States Timeline and periodsPrehistoric and Pre-Columbian Erauntil 1607Colonial Era 1607–17651776–1789 American Revolution 1765–1783 Confederation period 1783–1788 Industrial Revolution 1760s–19141789–1815 Federalist Era 1788–1801 Jeffersonian Era1801–18171815–1849 Era of Good Feelings 1817–1825 Jacksonian Era1825–18491849–1865 Civil War Era 1849–1865 Greater Reconstruction 1846–18981865–1917 Reconstruction Era 1865–1877 Gilded Age 1877–1896 Progressive Era 1896–19171917–1945 World War I 1917–1918 Roaring Twenties 1918–1929 Great Depression 1929–1941 Wo