when did new mexico become part of the us
New Mexico Territory The Territory of New Mexico was an organized incorporated territory of the United States that existed (with varying boundaries) from September 9, 1850, until January 6, 1912, when the remaining extent of the territory was admitted to the Union as the State of New Mexico, making it the longest-lived organized incorporated territory of the United States, lasting approximately 62 years.
Mexican–American War The Mexican–American War,[a] also known as the Mexican War in the United States and in Mexico as the American intervention in Mexico,[b] was an armed conflict between the United States of America and the United Mexican States (Mexico) from 1846 to 1848. It followed in the wake of the 1845 American annexation of the independent Republic of Texas. Mexico had considerable instability under the caudillo leadership of President/General Antonio López de Santa Anna, with many constitutional changes leading up to the conflict. Mexico still considered Texas to be its northeastern province and a part of its territory, and did not recognize the Republic of Texas, which had seceded from Mexico in the 1836 Texas Revolution a decade earlier. In 1845, newly elected U.S. President James K. Polk sent troops to the disputed area, and a diplomatic mission to Mexico. After Mexican forces attacked American forces, Polk cited this in his request that Congress declare war.