The Liberal Republican Party was an American political party that was organized in May 1872 to oppose the reelection of President Ulysses S. Grant and his Radical Republican supporters in the presidential election of 1872. The party emerged in Missouri under the leadership of Senator Carl Schurz and soon attracted other opponents of Grant; Liberal Republicans decried the scandals of the Grant administration and sought civil service reform. The party opposed Grant's Reconstruction policies, particularly the Enforcement Acts that destroyed the Ku Klux Klan. It lost in a landslide, and disappeared from the national stage after the 1872 election.

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.