James Polk's desire to gain territory in the West caused a battle over the expansion of slavery between North and South. The Wilmot Proviso, introduced by Democratic Representative David Wilmot of Pennsylvania on August 8, 1846 (just two months after the outbreak of war with Mexico), banned slavery anywhere in any territory that might be acquired from Mexico.

It was a hotly debated political issue. Polk and many other Southerners were against the Proviso. What was Polk's alternative to the Proviso?