Wilmot Proviso

The Wilmot Proviso was an unsuccessful 1846 proposal in the United States Congress to ban slavery in territory acquired from Mexico in the Mexican–American War.^[1] The conflict over the Wilmot Proviso was one of the major events leading to the American Civil War.

Congressman David Wilmot of Pennsylvania first introduced the proviso in the House of Representatives on August 8, 1846, as a rider on a $2,000,000 appropriations bill intended for the final negotiations to resolve the Mexican–American War (this was only three months into the two-year war). It passed the House largely on sectional lines between a generally anti-slavery North in favor and a pro-slavery South against, foreshadowing coming conflicts. It failed in the Senate, where the South had greater representation. The proviso was reintroduced in February 1847 and again passed the House and failed in the Senate. In 1848, an attempt to make it part of the Treaty of Guadalupe Hidalgo also failed. Sectional political disputes over slavery in the Southwest continued through the Compromise of 1850.