A letter from Feb 01, 2026

Dear FutureMe, On August 8, 1846, David Wilmot, a Democratic congressman from Pennsylvania, introduced a proposal to forbid slavery in any territory the United States might acquire during the Mexican War. Mexico itself had abolished slavery, and supporters of the Wilmot Proviso argued that the US government had no right to reinstate it. Large numbers of northern Democrats and Whigs proved willing to vote for Wilmot's proposal, defending the principle of nonextension of slavery and denouncing the Slave Power with growing determination. The Wilmot Proviso became a symbol of the extent to which northern Democrats, in particular, were willing to choose section over party. In 1847, Martin Van Buren's allies-known as the Barnburners-walked out of the New York State Democratic Convention when it failed to endorse the principle of nonextension of slavery. Members of the renegade group met a week later to register their grievances and declare "their uncompromising hostility to the extension of slavery into territory now free "50