http://en.wikipedia.org/wiki/Thaddeus_Stevens

Thaddeus Stevens (April 4, 1792 ΓÇô August 11, 1868), of Pennsylvania, was a leader of the Radical Republican faction of the Republican Party and a fierce opponent of slavery. He was one of the most influential members in the history of Congress. As chairman of the powerful House Ways and Means Committee, Stevens, a witty, sarcastic speaker and flamboyant party leader, dominated the House from 1861 until his death. He wrote much of the financial legislation that paid for the American Civil War. Stevens and Senator Charles Sumner were the prime leaders of the Radical Republicans during the war and Reconstruction era.

Scholarly views of Stevens have swung sharply since his death as interpretations of Reconstruction have changed. Historians of the Dunning School (1890sΓÇô1940s) held Stevens responsible for demanding harsh treatment of the white South and violating American traditions of republicanism, depicting Stevens as a villain for his advocacy of harsh measures in the South such as disfranchising all ex-Confederates. This highly negative characterization held sway into the 1950s.[1] The rise of the neo-abolitionist school in the 1950s[2] led to a strong positive appreciation of Stevens' work on civil rights for Freedmen. A recent biographer characterizes him as, "The Great Commoner, savior of free public education in Pennsylvania, national Republican leader in the struggles against slavery in the United States and intrepid mainstay of the attempt to secure racial justice for the Freedmen during Reconstruction, the only member of the House of Representatives ever to have been known as the 'dictator' of Congress."[3]