Mr. Clay's letter had made him stronger than ever with his party and he was nominated unanimously. The Whig Platform, however, was absolutely silent about the Texas question, and there was absolutely no mention of any opposition to slavery; the whole question was totally ignored. Mr. Clay would have defeated Polk had he not been led into the blunder of writing another letter on the Texas question, in which he largely withdrew from his earlier position; this alienated great numbers of the Northern Whigs and threw thousands of votes to the candidate of the Liberty Party. This party, in a convention at Buffalo the preceding year, had again nominated James G. Birney for President. Its platform was long and elaborate, and contained strong denunciations of slavery and pledged the party to work for its abolition. The Liberty Party polled a total of 62,300 votes, defeating Clay, who lost New York, the pivotal State, with its thirty-six electoral votes, by 5,106, the Liberty Party casting 15,812 votes in that State. Texas annexation followed the election, but the pledge in regard to Oregon was cast aside. "Fifty-four Forty or Fight" was nothing more than a campaign cry, never intended to be followed up, and, in truth, could not have been without a war with England. With the great Texas victory achieved, the South now turned herself to the acquisition of more territory, and war with Mexico was declared May 11, 1846. The Whig Party in the North was strongly against the Mexican War, and a strong element also expressed itself in the northern Democratic ranks as against it; the opposition became so threatening that, as a new House was to be elected in the Fall of 1846, the Administration decided to end the War, if possible, and Congress was asked to give $2,000,000 to be used in negotiating a Treaty with Mexico, fixing the disputed boundaries. Immediately David Wilmot, of Pennsylvania, introduced a Proviso, which had been prepared by Jacob Brinkerhoff, of Ohio (both Democrats, and both afterwards members of the Republican Party), to the effect that slavery should be prohibited in any territory acquired from Mexico. This Proviso carried in the House, but the Senate adjourned its session without coming to a vote on it. The Proviso appeared again often in Congress, but was never adopted; it caused more excited debate between the North and South than anything that had ever been introduced by the anti-slavery element in Congress. Although defeated, it served to amalgamate the anti-slavery forces, and from that day they rallied around it as representing the fixed and unalterable sentiment of the North; on it the Free-Soil Party entered the Campaign of 1848 and it was the underlying principle in the organization of the Republican Party in 1854. As a counter-balancing action to the Wilmot Proviso, Mr. Calhoun, in February, 1847, introduced in the Senate a long resolution to the effect that Congress had no power