Texas Annexed
After the landslide victory of James Polk, who ran on a ticket supporting annexation of Texas, Congress approved the annexation by joint resolution. In years past, Congress had blocked the Tylers' treaties for these annexations.
After Texas secured its independence, the US refused to admit it into the Union. Therefore Texas was forced to maintain a large army and make treaties with France, Holland, and Belgium to insure its continued independence. It entered into negotiations with the British, who were very interested in supporting an independent Texas. The threat of British interest helped renew American interest in Texas.
The annexation of Texas was one of the campaign pledges of the Democratic party in the 1844 election. Tyler considered the Democratic victory to be an endorsement of this policy. Thus, after the Democratic victory, Tyler rushed a joint resolution through Congress mandating the annexation. He did this despite the opposition of many Northerners to adding an additional slave state to the Union. There was an implied implication in the annexation that it would sooner or later result in war with Mexico.