Missouri was admitted as a slave state while Maine, previously part of Massachusetts, was admitted as a free state to preserve the numerical balance in the Senate. In addition, Congress established a geographical boundary in the remaining Louisiana Purchase territory that meant slavery was prohibited north of latitude 36°30′.

Daniel Webster’s “Seventh of March” speech saw the prominent senator from Massachusetts, who was a staunch defender of the Union, deliver an address endorsing the compromise measures as a means to preserve national unity and avert a possible civil war.