Respuesta :

In the Mexican-American War, Mexico faced an enemy that was coming into its own as a military power. In March 1836, Mexican forces overran the Alamo in San Antonio, Texas, achieving victory over those who had declared Texas independence from Mexico just a few weeks earlier

Answer:

They lost it in the Mexican-American War. The treaty of Guadalupe-Hidalgo gave the US Texas in 1848 among other land. This is also known as the Annexation of Texas.

Explanation:

US History