Wilmot Proviso, 1846
Representative David Wilmot of Pennsylvania introduced an amendment to prohibit slavery in the territory acquired from Mexico. The amendment failed, but the issue of slavery dominated congresses in the 1850s.
Records of the U.S. House of Representatives, National Archives and Records Administration, Washington, D.C.
Taking a Stand, 1848
Adding controversial amendments to important bills is one tactic used by supporters of a bill to make other lawmakers confront and vote on difficult issues. Representative David Wilmot of Pennsylvania used this technique in a classic example of parliamentary acrobatics. In 1846, Wilmot successfully added to an appropriations bill (one that authorizes necessary government expenditures) an amendment prohibiting slavery in all territory taken during the Mexican War. The Senate, where the South was stronger, let the bill die. The antislavery House majority continued adding Wilmot’s proviso to other important bills, constantly forcing legislators to face the volatile question of expanding slavery.