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The Wilmot Proviso was a proposal for an act prohibiting slavery in areas joined to the Union as a result of the war with Mexico.
Adhering to the idea of Revealed Destiny, James Polk sought to expand the territory of the states of the Union. To this end, in 1846, he tried to buy New Mexico and California territory for Mexico for $ 30 million. Faced with the refusal, the president provoked hostilities which led to the official declaration of war by Congress. After some time, Polk asked both houses of Parliament to pay $ 2 million for peace negotiations and establishing a border with Mexico. On August 8, 1846, a member of the House of Representatives of the Democratic Party, David Wilmot, submitted a motion to enact a law prohibiting slavery in all newly annexed areas. This clause was voted twice in the lower chamber (in 1846 and 1847), but each time the Senate did not agree to its adoption. In addition to the industrialized North, Western Democrats also voted in favor of the bill, accusing the President's secret alliance with the South and signing the Walker Customs Act, which reduced tariffs. Abolitionists from the North believed that the ban on slavery was within Congress's competence.
The law was never successfully voted, but disputes in both main parties, resulting from an attempt to regulate slavery, led to the creation of the Republican Party, which strongly supported the clause.
