Question: what was the impact of the annexation of texas

title: Texas annexation
text: 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 . The bill was signed by Polk on December 29 , 1845 , accepting Texas as the 28th state of the Union . Texas formally relinquished its sovereignty to the United States on February 19 , 1846 . Following the annexation , relations between the United States and Mexico deteriorated due to an unresolved dispute over the border between Texas and Mexico , and the Mexican - American War broke out only a few months later .