This was the celebrated Wilmot Proviso, which for so long a time convulsed the Union; assisted in forcing the issue between the North and South on the slavery question, and almost caused a dissolution of the Union. The proviso was defeated; that chance of the nullifiers to force the issue was lost; another had to be made, which was speedily done, by the introduction into the Senate on the 19th February, 1847, by Mr. Calhoun of his new slavery resolutions, declaring the Territories to be the common property of the several States; denying the right of Congress to prohibit slavery in a Territory, or to pass any law which would have the effect to deprive the citizens of any slave State from emigrating with his property (slaves) into such Territory. The introduction of the resolutions was prefaced by an elaborate speech by Mr. Calhoun, who demanded an immediate vote upon them. They never came to a vote; they were evidently introduced for the mere purpose of carrying a question to the slave States on which they could be formed into a unit against the free States; and so began the agitation which finally led to the abrogation of the Missouri Compromise line, and arrayed the States of one section against those of the other. The Thirtieth Congress, which assembled for its first session in December, 1847, was found, so far as respects the House of Representatives, to be politically adverse to the administration. The Whigs were in the majority, and elected the Speaker; Robert C. Winthrop, of Massachusetts, being chosen. The President’s message contained a full report of the progress of the war with Mexico; the success of the American arms in that conflict; the victory of Cerro Gordo, and the capture of the City of Mexico; and that negotiations were then pending for a treaty of peace. The message concluded with a reference to the excellent results from the independent treasury system. The war with Mexico was ended by the signing of a treaty of peace, in February, 1848, by the terms of which New Mexico and Upper California were ceded to the United States, and the lower Rio Grande, from its mouth to El Paso, taken for the boundary of Texas. For the territory thus acquired, the United States agreed to pay to Mexico the sum of fifteen million dollars, in five annual installments; and besides that, assumed the claims of American citizens against Mexico, limited to three and a quarter million dollars, out of and on account of which claims the war ostensibly originated. The victories achieved by the American commanders, Generals Zachary Taylor and Winfield Scott, during that war, won for them national reputations, by means of which they were brought prominently forward for the Presidential succession.