USA HISTORY

Detailed explanation-1: -It stemmed from the annexation of the Republic of Texas by the U.S. in 1845 and from a dispute over whether Texas ended at the Nueces River (the Mexican claim) or the Rio Grande (the U.S. claim).

Detailed explanation-2: -In 1845 the United States annexed Texas and subsequently engaged in a dispute with Mexico over the southern Texas-Mexico border. Texas claimed that its southwest boundary extended to the Rio Grande. Mexico claimed that the boundary was the Nueces River, which is 100 miles (160 kilometers) eastward.

Detailed explanation-3: -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.

Detailed explanation-4: -The Mexican-American War of 1846-1848 was a combination of Mexican unwillingness to recognize Texas independence, the desire of Texans for statehood, and American desire for westward expansion.

Detailed explanation-5: -Mexico, who refused to formally recognize Texas’ independence in the first place, pushed back against Texas’ desire to set their Republic’s border at the Río Grande. Mexico contested that Texas had to move the line back to the Nueces River, which runs through modern day Corpus Christi.