Radical Republicans were certain Republicans in Congress and other federal and state leaders during the American Civil War and Reconstruction eras in U.S. history.

Radical Republicans believed in total emancipation and that freed slaves should have equality with all other citizens. In addition, they believed that punitive measures should be taken against the Southern states for seceding from the Union. After the 1860 elections, Radical Republicans dominated the United States Congress. Radical Republicans were often critical of President Abraham Lincoln, whom they felt was too slow in freeing slaves and supporting their equality. However, Lincoln had Radical Republicans in his cabinet, including Treasury Secretary, Salmon P. Chase (whom Lincoln later appointed to the Supreme Court), Edwin M. Stanton and James Speed.

Following the Civil War, during Reconstruction, Radical Republicans in Congress were in favor of harsher measures concerning the South than was the president, and there is much historical speculation as to how Reconstruction would have proceeded if Lincoln had not been assassinated. Following Lincoln's assassination, Andrew Johnson became President, and differences over Reconstruction policy became clear when Congress passed measures dealing with the former slaves over Johnson's veto —the first time that Congress had overridden a President on an important bill. Radicals also passed the Civil Rights Act of 1866, which established African-Americans as American citizens and forbade discrimination against them. The 14th Amendment to the United States Constitution (with its equal protection clause) was also the work of the Radical Republicans.

The Radical Republicans led the Reconstruction of the South and the impeachment of President Andrew Johnson, and had an influence on future presidents including Ulysses S. Grant.

Following the Civil War, however, Radical Republicans collapsed and following the U.S. presidential election of 1876, the influence of the Radical Republicans waned and died.

The Radical Republicans were viewed as outrageous in their own time, but their progressive goals (of civil rights and equal treatment for African-Americans following emancipation) were in fact almost universally realized within the United States over the following 100 years.

Famous Radical Republicans

• Charles Sumner: Senator who was beaten on the floor of the Senate by South Carolina Congressman Preston Brooks.
• John Bingham: Congressman from Ohio, principal framer of the Fourteenth Amendment to the United States Constitution.
• Benjamin Wade: Extremely radical presiding officer of the Senate.
• Thaddeus Stevens: Outspoken, radical Congressman.
• Benjamin Butler: Infamous general (and later Senator) who allowed the pillaging of Southern cities, sometimes called the "Damnedest Yankee"
• Henry Wilson
• Salmon P. Chase
• Elihu Washburne: Senator who persuaded future President Grant to enter military service.
• James A. Garfield: Future President who was less radical than others; disliked Benjamin Wade.
• Hannibal Hamlin: First Vice President of Abraham Lincoln.
• Henry Winter Davis
• Zachariah Chandler: U.S. Senator from Michigan and Secretary of the Interior under Ulysses S. Grant.

See also

• Radical Reconstruction
• Origins of the American Civil War
• National Union Convention