USA HISTORY

Detailed explanation-1: -By the Treaties of Velasco made after Texans captured General Santa Ana after the Battle of San Jacinto, the southern border of Texas was placed at the “Rio Grande del Norte.” The Texans claimed this placed the southern border at the modern Rio Grande.

Detailed explanation-2: -Texas claimed the Rio Grande as its southern border. Mexico said the Nueces River, to the north, should be the border.

Detailed explanation-3: -The Rio Grande serves as the border here. “The Rio Grande is a natural border, has been since 1848, and the ties between cities and towns on either side are strong, ” CNN’s Gregory Krieg reported.

Detailed explanation-4: -Mexico also relinquished all claims to Texas, and recognized the Rio Grande as the southern boundary with the United States.

Detailed explanation-5: -Mexican–American War The annexation bill did not specifically define the boundaries of Texas. The former republic claimed the Rio Grande as its southern border, while Mexican authorities had always considered the Nueces River, situated further north, to be the boundary of Mexican Texas.