The Wilmot Proviso (1846) was an amendment to a bill put before the U.S. House of
Representatives during the Mexican War; it provided an appropriation of $2
million to enable President Polk to negotiate a territorial settlement with
Mexico. David Wilmot introduced an amendment to the bill stipulating that
none of the territory acquired in the Mexican War should be open to slavery.
The amended bill was passed in the House, but the Senate adjourned
without voting on it. In the next session of Congress (1847), a new bill
providing for a $3 million appropriation was introduced, and Wilmot again
proposed an antislavery amendment to it. The amended bill passed the
House, but the Senate drew up its own bill, which excluded the proviso. The
Wilmot Proviso created great bitterness between North and South and
helped crystallize the conflict over the extension of slavery. In the election
of 1848 the terms of the Wilmot Proviso, a definite challenge to proslavery
groups, were ignored by the Whig and Democratic parties, but were adopted
by the 'Free-Soil' party . Later the Republican party also favored excluding
slavery from new territories.