The Wade–Davis Bill of 1864 (H.R. 244) was a bill "to guarantee to certain States whose governments have been usurped or overthrown a republican form of government," proposed for the Reconstruction of the South. In opposition to President Abraham Lincoln's more lenient ten percent plan, the bill made re-admittance to the Union for former Confederate states contingent on a majority in each ex-Confederate state to take the Ironclad Oath to the effect they had never in the past supported the Confederacy. The bill passed both houses of Congress on July 2, 1864, but was pocket vetoed by Lincoln and never took effect. The Radical Republicans were outraged that Lincoln did not sign the bill. Lincoln wanted to mend the Union by carrying out the ten percent plan. He believed it would be too difficult to repair all of the ties within the Union if the Wade–Davis bill passed.

The Radical Republicans were a 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 goal of immediate, complete, and permanent eradication of slavery in the United States. They were opposed during the war by the Moderate Republicans, and by the Democratic Party. 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 rebel states, Radicals pushed the Fourteenth Amendment for statutory protections through Congress. They opposed allowing ex-Confederate officers 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.