“I owe a paramount allegiance to the whole Union——a subordinate one to my own State.”

Senator Henry Clay, July 22, 1850

By 1850 sectional disagreements centering on slavery were straining the bonds of union between the North and South. These tensions became especially acute when Congress began to consider whether western lands acquired after the Mexican War would permit slavery. In 1849 California requested permission to enter the Union as a free state. Adding more free state senators to Congress would destroy the balance between slave and free states that had existed since the Missouri Compromise of 1820.

Because everyone looked to the Senate to defuse the growing crisis, Senator Henry Clay of Kentucky proposed a series of resolutions designed to "Adjust amicably all existing questions of controversy . . . arising out of the institution of slavery." Clay attempted to frame his compromise so that nationally-minded senators would vote for legislation in the interest of the Union.

In one of the most famous congressional debates in American history, the Senate discussed Clay’s solution for 7 months. It initially voted down his legislative package, but Senator Stephen A. Douglas of Illinois stepped forward with substitute bills, which passed both Houses. With the Compromise of 1850, Congress had addressed the immediate crisis created by territorial expansion. But one aspect of the compromise——a strengthened Fugitive Slave Act——soon began to tear at sectional peace.