Why did the Wilmot proviso do?

The Wilmot Proviso was an 1846 legislative proposal aimed at banning slavery in any territory acquired from Mexico during the Mexican-American War. Introduced by Congressman David Wilmot, it sought to prevent the expansion of slavery into these newly acquired lands. Although it did not pass in Congress, the proviso intensified the national debate over slavery, contributing to the sectional tensions that eventually led to the Civil War. Its introduction highlighted the deep divisions between free and slave states in the United States.