Texas annexation

The Texas annexation was the incorporation of the Republic of Texas into the United States, culminating in its admission to the Union as the 28th state on December 29, 1845. The Republic of Texas had declared independence from Mexico on March 2, 1836. President John Tyler secured an annexation treaty in April 1844, but the Senate rejected it, and annexation became the central issue of the 1844 presidential election, which was won by pro-annexation candidate James K. Polk. Tyler then signed a joint resolution of Congress on March 1, 1845, Texas ratified the agreement, and President Polk signed it into law in December 1845. The annexation prompted the Mexican-American War in 1846.