Attracted by fertility of soil and advantages for cattle-raising, large numbers of Americans had long been emigrating to Texas. By 1830 they probably comprised a majority of its inhabitants. March 2, 1836, Texas declared its independence of Mexico, and on April 10th of that year fought in defence of the same the decisive battle of San Jacinto. Here Houston gained a complete victory over Santa Anna, the Mexican President, captured him, and extorted his signature to a treaty acknowledging Texan independence. This, however, as having been forced, the Mexican Government would not ratify. [1845] Not only did the Texans almost to a man wish annexation to our Union, but, as we have seen, the dominant wing of the democratic party in the Union itself was bent upon the same, forcing a demand for this into their national platform in 1840. Van Buren did not favor it, which was the sole reason why he forfeited to Polk the democratic nomination in 1844. Polk was elected by free-soil votes cast for Birney, which, had Clay received them, would have carried New York and Michigan for him and thus elected him; but the result was hailed as indorsing annexation. Calhoun, Tyler's Secretary of State, more influential than any other one man in bringing it about, therefore now advocated it more zealously than ever. Calhoun's purpose in this was to balance the immense growth of the North by adding to southern territory Texas, which would of course become a slave State, and perhaps in time make several States. As the war progressed he grew moderate, out of fear that the South's show of territorial greed would give the North just excuse for sectional measures. [Illustration: Portrait.] General Sam. Houston. Henry Clay, with nearly the entire Whig Party, from the first opposed the Tyler-Calhoun programme. Clay's own reason for this, as his memorable Lexington speech in 1847 disclosed, was that the United States would be looked upon "as actuated by a spirit of rapacity and an inordinate desire for territorial aggrandizement." His party as a whole dreaded more the increment which would come to the slave power. After much discussion in Congress, Texas was annexed to the Union on January 25, 1845, just previous to Polk's accession. June 18th, the Texan Congress unanimously assented, its act being ratified July 4th by a popular convention. Thus were added to the United States 376,133 square miles of territory. [Illustration: Portrait.] General Santa Anna.