From the Annals of Statehood – In 1844, the U.S. Senate rejected a treaty providing for the annexation of Texas. Texas’ annexation was a hot political issue of the day because it meant the addition of a vast slave-holding state to the Union. Both the Democrats and Whigs had opposed annexation understanding that it would further inflame tensions between the free and slave states. However, President John Tyler began to promote annexation as a gambit to gain support for a second presidential term. Tyler had abandoned the Whig party by this point and believed that pursuing annexation of Texas would create a groundswell of popular support among slave states and secure him another four years in office. He began secret negotiations with Sam Houston’s administration and ultimately secured a treaty of annexation in April 1844. When the terms became public, the 1844 became something of a referendum on the issue of annexation. Pro-annexation southern Democratic delegates rejected Tyler and the anti-annexation leader Martin Van Buren at their party’s convention in May 1844, instead nominating pro-annexation James K. Polk who ran on a pro-Texas Manifest Destiny platform.
In June 1844, the Senate, with its Whig majority, rejected the Tyler–Texas treaty and in the Fall elections Polk narrowly defeated anti-annexation Whig Henry Clay. In December 1844, lame-duck President Tyler once again attempted to gain passage of the treaty. He called on Congress to pass his treaty by simple majorities in each house. The Democratic-dominated House of Representatives passed a bill expanding on the pro-slavery provisions of the Tyler treaty. The Senate narrowly passed a compromise version of the House bill (by the vote of the minority Democrats and several southern Whigs), designed to provide the incoming President-elect Polk the options of immediate annexation of Texas or new talks to revise the annexation terms of the House-amended bill. On March 1, 1845, President Tyler signed the annexation bill, and on March 3 (his last day in office), he forwarded the House version to Texas, offering immediate annexation (which preempted Polk). When Polk took office the next day, he encouraged Texas to accept the Tyler offer. Texas ratified the agreement with popular approval from Texans.