Thaddeus Stevens (1792-1868), American congressman, was the leading Radical Republican in the Civil War era.

Thaddeus Stevens, the son of an unsuccessful farmer who subsequently deserted his family, was born on April 4, 1792, in Danville, Vt. Despite his impoverished background and a deformity of the feet, he graduated from Dartmouth in 1814 and became a successful lawyer in Gettysburg, Pa. An Anti-Mason, he became a Whig when that party absorbed his in the mid-1830s. Elected to the state legislature in 1833, he remained for 8 years, becoming noted for his campaign to extend the state's free school system. An early and intense opponent of slavery, he defended fugitive slaves in the courts and, at the Pennsylvania constitutional convention of 1837, unsuccessfully fought black disenfranchisement.

Stevens's intelligence and absolute mastery of political invective made him a frequent spokesman for his party, but his occasional erratic and impulsive actions and his singular ability to...