how did the us acquire texas

The United States acquired Texas through annexation after Texas had declared its independence from Mexico in 1836. Texas existed as an independent republic and sought to join the United States, but initial attempts were rejected due to political concerns over slavery and potential conflict with Mexico. The process moved forward under President John Tyler, who secured a treaty for annexation in 1844, though the Senate initially rejected it. Later, under President James K. Polk, who supported annexation as part of his expansionist policy, Congress passed a joint resolution to annex Texas in 1845. Texas ratified the annexation agreement and was admitted to the Union as the 28th state on December 29, 1845. Texas formally joined the U.S. in 1846, which contributed to the outbreak of the Mexican-American War, as Mexico did not recognize Texas's independence or its annexation by the United States.