Radical Republicans

The Radical Republicans were a political faction within the Republican Party originating from the party's founding in 1854—some six years before the Civil War—until the Compromise of 1877, which effectively ended Reconstruction. They called themselves "Radicals" because of their determinations to facilitate the rapid, complete, and permanent eradication of slavery in the United States through constitutional means, without resorting to a direct legislative or executive assault on the institution in established slave states. Their peacetime political approach was to exclude slavery from areas under federal government authority, including territorial lands, the District of Columbia and international waters so as to confine slavery within its existing state boundaries. There the institution was expected to decline and undergo dismantling by the state governments themselves with federal encouragement. Radical Republicans of the 1850s exhibited "a persistent refusal to compromise with the South on any question involving slavery," insisting upon a "denationalization" of the institution. When war broke out in 1861, radicals supported immediate military emancipation of slaves in the rebellious states

On the issues of nativism, anti-Catholicism and prohibition of alcoholic beverages, radical Republicans regarded these as distractions or impediments to their abiding mission to eradicate slavery. Though many Republicans held anti-immigrant, anti-Catholic, and pro-temperance sentiments, they emphatically opposed these becoming politicized and alienating key demographics that they wished to enlist in the anti-slavery cause. To the extent that radicals tolerated nativism, it was largely that the nativists Know-Nothings were expected to undermine the Whig and Democratic Parties and clear the way for the rise of the Republican Party. Nativists ultimately cast their votes for Republican politicians, their ideology was never embraced by the party establishment which regarded them with suspicion.

In the late 1850s, moderate Republicans drew closer to the radical wing of the party in their hostility toward the Slave Power.

Moderates also saw the political utility of stressing the moral injustice of slavery stressed by radicals. By 1860, Lincoln was considered to be closer to the radicals than the conservative wing of the party. During the secession crisis that unfolded after Lincoln's election, radicals initially rejected the moderate and conservative wings' efforts to placate southerners with concessions. Neither the radical anti-compromise position nor the moderates' limited conciliation satisfied the South. The right and left wings of the Republican Party coalesced under Lincoln's moderate wing: "The goals of free soil and Union were intertwined, and neither could be sacrificed without endangering the other."

Radicals led efforts after the war to establish civil rights for former slaves and fully implement emancipation. After unsuccessful measures in 1866 resulted in violence against former slaves in the former rebel states, Radicals pushed the Fourteenth Amendment for statutory protections through Congress. They opposed allowing ex-Confederate politicians and military veterans to retake political power in the Southern U.S., and emphasized equality, civil rights and voting rights for the "freedmen", i.e., former slaves who had been freed during or after the Civil War by the Emancipation Proclamation and the Thirteenth Amendment.

During the war, Radicals opposed Lincoln's initial selection of General George B. McClellan for top command of the major eastern Army of the Potomac and Lincoln's efforts in 1864 to bring seceded Southern states back into the Union as quickly and easily as possible. Lincoln later recognized McClellan as unfit and relieved him of his command. The Radicals tried passing their own Reconstruction plan through Congress in 1864. Lincoln vetoed it, as he was putting his own policy in effect through his power as military commander-in-chief. Lincoln was assassinated in April 1865. Radicals demanded for the uncompensated abolition of slavery, while Lincoln wished instead to partially emulate the British Empire's abolition of slavery by financially compensating former slave owners who had remained loyal to the Union. The Radicals, led by Thaddeus Stevens, bitterly fought Lincoln's successor, Andrew Johnson. After Johnson vetoed various congressional acts favoring citizenship for freedmen, a much harsher Reconstruction for the defeated South, and other bills he considered unconstitutional, the Radicals attempted to remove him from office through impeachment, which failed by one vote in 1868.

During the Reconstruction period, Radical Republicans supported prolabor legislation, in contrast to conservative Democrats and Liberal Republicans.