In the United States, the Wilmot Proviso, first suggested in 1846 and attached to many bills but never passed, would have outlawed slavery in any U.S. territory gained by the recently completed Mexican-American War. It was first suggested by Congressman David Wilmot of Pennsylvania, which gave the proviso its name. The Free Soil Party formed in support of the Wilmot Proviso, and their platform of Free soil was later adopted by the Republican Party.
