Wilmot Proviso, << WIHL muht pruh VY zoh, >> was an amendment proposed in 1846 that would have banned slavery in any territory acquired by the United States from Mexico. David Wilmot, a Democratic representative from Pennsylvania, offered the amendment to a bill proposed by President James K. Polk. Polk asked Congress to appropriate $2 million to negotiate peace with Mexico, then at war with the United States. He hoped to use this money as compensation for land the United States expected to acquire from Mexico. The Wilmot Proviso declared that slavery should be forbidden in any territory obtained with the money.
The House of Representatives approved the amendment on Feb. 15, 1847. But the Senate, where Southern representation was stronger, refused to pass it. For several years, the Wilmot Proviso was offered unsuccessfully as an amendment to many bills. It reopened the bitter debate over the issue of slavery in the territories. The issue was settled in 1862, when Congress banned slavery in any U.S. territory.