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. The conflict over the Wilmot Proviso was one of the major events leading to the American Civil War.

The United States House of Representatives is the lower chamber of the United States Congress, with the Senate being the upper chamber. Together, they comprise the national bicameral legislature of the United States. The House is charged with the passage of federal legislation, known as bills; those that are also passed by the Senate are sent to the president for signature or veto. The House's exclusive powers include initiating all revenue bills, impeaching federal officers, and electing the president if no candidate receives a majority of votes in the Electoral College.