The Wilmot Proviso was a legislative proposal introduced in 1846 by Congressman David Wilmot during the Mexican-American War. It aimed to ban slavery in any territory acquired from Mexico, reflecting the growing tensions between free and slave states in the United States. The proviso sparked intense debates in Congress and highlighted the sectional conflicts over the expansion of slavery. Although the Wilmot Proviso never passed, it played a significant role in shaping the political landscape of the time. It contributed to the formation of the Republican Party and intensified the national conversation about slavery, ultimately leading to the Civil War.