Answer:
Texas was annexed by the United States in 1845 and became the 28th state.
Until 1836, Texas had been part of Mexico, but in that year a group of settlers from the United States who lived in Mexican Texas declared independence. They called their new country the Republic of Texas, which was an independent country for nine years.
Politics in the United States fractured over the issue of whether Texas should be admitted as a slave or free state. In the end, Texas was admitted to the United States a slave state.
The annexation of Texas contributed to the coming of the Mexican-American War (1846-1848). The conflict started, in part, over a disagreement about which river was Mexico’s true northern border: the Nueces or the Rio Grande.
Explanation:
But the United States’ annexation of Texas was not the end of the story. In the spring of 1846, tensions mounted between the United States and Mexico, and the Mexican-American War (1846-1848) started, in part, over a border dispute between the two countries. Mexico claimed the Nueces River to be Texas’s southern border, but the United States insisted the border lay further south at the Rio Grande River.
The Mexican-American War confirmed Texas’s southern border at the Rio Grande, indicating the United States victory. The United States also acquired California, New Mexico, and Arizona, as well as parts of Nevada, Utah, Colorado and Wyoming.
