It so happened, however, that the events which, it was thought, would secure slavery let loose a storm against it.  A sign appeared first on August 6, 1846, only a few months after war was declared on Mexico.  On that day, David Wilmot, a Democrat from Pennsylvania, introduced into the House of Representatives a resolution to the effect that, as an express and fundamental condition to the acquisition of any territory from the republic of Mexico, slavery should be forever excluded from every part of it.  “The Wilmot Proviso,” as the resolution was popularly called, though defeated on that occasion, was a challenge to the South.

The South answered the challenge.  Speaking in the House of Representatives, Robert Toombs of Georgia boldly declared:  “In the presence of the living God, if by your legislation you seek to drive us from the territories of California and New Mexico ...  I am for disunion.”  South Carolina announced that the day for talk had passed and the time had come to join her sister states “in resisting the application of the Wilmot Proviso at any and all hazards.”  A conference, assembled at Jackson, Mississippi, in the autumn of 1849, called a general convention of Southern states to meet at Nashville the following summer.  The avowed purpose was to arrest “the course of aggression” and, if that was not possible, to provide “in the last resort for their separate welfare by the formation of a compact and union that will afford protection to their liberties and rights.”  States that had spurned South Carolina’s plea for nullification in 1832 responded to this new appeal with alacrity—­an augury of the secession to come.

[Illustration:  From an old print.

HENRY CLAY]

=The Great Debate of 1850.=—­The temper of the country was white hot when Congress convened in December, 1849.  It was a memorable session, memorable for the great men who took part in the debates and memorable for the grand Compromise of 1850 which it produced.  In the Senate sat for the last time three heroic figures:  Webster from the North, Calhoun from the South, and Clay from a border state.  For nearly forty years these three had been leaders of men.  All had grown old and gray in service.  Calhoun was already broken in health and in a few months was to be borne from the political arena forever.  Clay and Webster had but two more years in their allotted span.

Experience, learning, statecraft—­all these things they now marshaled in a mighty effort to solve the slavery problem.  On January 29, 1850, Clay offered to the Senate a compromise granting concessions to both sides; and a few days later, in a powerful oration, he made a passionate appeal for a union of hearts through mutual sacrifices.  Calhoun relentlessly demanded the full measure of justice for the South:  equal rights in the territories bought by common blood; the return of runaway slaves as required by the Constitution; the suppression of the abolitionists; and the restoration