Answer:
At the conclusion of The Mexian-American War in 1848
Step-by-step explanation:
At the same time, the region became more economically dependent on the United States. At the conclusion of the Mexican–American War in 1848, the United States annexed New Mexico as the U.S. New Mexico Territory. It was admitted to the Union as the 47th state on January 6, 1912. (Cited Via Wikipedia & Answers