“Mr. President, never on any former occasion have I risen under feelings of such painful solicitude.” With these words—sounding hyperbolic, yet if anything an understatement—on February 5 Henry Clay of Kentucky rose in the Senate and began the most critical speech of his long and illustrious career. A week earlier he had introduced a set of resolutions designed to end the nation’s strife over slavery. The main provisions would admit California as a free state, leave the territory of New Mexico’s slavery status unspecified, strengthen the fugitive slave law, and essentially prohibit the sale of slaves in the District of Columbia. In an impassioned oration that stretched over two days, Clay defended his plan against opponents on all sides.

The Senate debate over Clay’s package, which came to be known as the Compromise of 1850, was the last major battle for three titans of American politics: Clay, John Calhoun of South Carolina, and Daniel Webster of Massachusetts. All three had been born during the Revolutionary War; all three could remember President Washington. To them the blood of patriots and the ideals of the Revolution were real, not stock images to be summoned up on the Fourth of July. After four decades together at the forefront of American politics, each of these aging statesmen would make one last effort to preserve the sacred principles of the Republic as he saw them.

For clay, the genius of the American Union was compromise, accommodation, and working together for prosperity. From a muddy rural upbringing, Clay had lived to see a nation that spanned the continent, dotted with factories and knit together by railroads, turnpikes, and steamboats. The prospect of his beloved Union’s abandoning everything it had achieved made him desperate to find a solution.

Paradoxically, Clay’s argument for his compromise rested on its lack of real effect. Slavery’s absence in California, he said, was a fait accompli enacted by a unanimous legislature. In barren New Mexico the institution could never take root. With Maryland and Virginia nearby, the ban on slave sales in the District of Columbia would be of little account. As for the return of fugitive slaves, the Constitution already required it. Were any of these points worth fighting over?

On March 4 came Calhoun’s turn. As a boy he had heard tales of his relatives fighting in the Revolution; his very name came from an uncle murdered by Tories. To him States’ Rights were an indispensable bulwark against the tyranny his ancestors had vanquished. Severely ill with tuberculosis and weakened by political exertions, Calhoun apologized for being unable to deliver his speech himself. Then, as the silent, cadaverous figure sat hunched at his desk, Sen. James Mason of Virginia read Calhoun’s remarks.

They began by tracing the North’s long record of encroachments on the rights of the