Henry Clay in Manifest Destiny & Mexican-American War
Henry Clay (1777–1852), who has been called the "Great Pacificator" and the "Great Compromiser," was a U.S. congressman, senator, statesman, and a twice-unsuccessful presidential candidate from the Whig Party (in 1832 and 1844).
In 1844, Clay lost by the slimmest of margins in his presidential campaign against James Polk. Clay suffered especially for his party's lack of any coherent position on the Texas annexation controversy. In two published letters, Clay opposed the annexation of Texas because, he argued, it posed a danger to the "integrity of the Union."
Having ushered Congress through the Missouri Compromise and the nullification crisis, Clay was all too aware of the potentially divisive effects that controversies over slavery could have if reintroduced on the national stage. So, the Whig party platform in 1844 didn't reference Texas at all, until Clay attempted to readjust his position in the "Alabama letters," in which he said he would support annexation if it could be accomplished with the common consent of the Union and without war. He was attempting to satisfy the pro-annexation, proslavery electorate in the South without losing his Northern supporters.
The effort failed—his support in New York suffered from this change of position. After the election, Clay went on to oppose war with Mexico, but he voted for war resolutions after the fighting began. Clay wanted to run for the presidency again in 1848, but instead, the Whigs nominated popular war hero Zachary Taylor.