USA HISTORY

Detailed explanation-1: -Texas used the Adams-Onís as a boundary line to the U.S., but decided to set the Rio Grande (called the Río Bravo del Norte in Mexico) as its boundary line to Mexico.

Detailed explanation-2: -Texas claimed the Rio Grande as its southern border. Mexico said the Nueces River, to the north, should be the border. The dispute simmered until Dec. 29, 1845, when the U.S. annexed the Lone Star State, and sent troops to the Rio Grande a month later.

Detailed explanation-3: -Citation: Treaty of Guadalupe Hidalgo [Exchange copy]; 2/2/1848; Perfected Treaties, 1778-1945; General Records of the United States Government, Record Group 11; National Archives Building, Washington, DC.

Detailed explanation-4: -After the Mexican-American War-during Texas’ first round of being a U.S. state-the 1848 Treaty of Guadalupe-Hidalgo established the Rio Grande as the border between the United States and Mexico. People living along some parts of the river woke up as part of a different country.

Detailed explanation-5: -Mexico claimed that the southern boundary of Texas was the Nueces River, the Texan boundary while under Mexican rule. Americans, as well as the incoming President, claimed that the boundary of Texas was the Rio Grande River.