Mexico did not take kindly to American troops crossing the Nueces River and building a fort on the Rio Grande. They quickly sent troops across the Rio Grande to drive the Americans away. They attacked and defeated numerous American patrols, and America declared war soon thereafter. Numerous Texas forces volunteered to join the war effort, including many of their respected cavalry units and the Rangers. The far better equipped American Army quickly smashed through the poorly equipped Mexican Army and occupied New Mexico and California. They marched south of the Rio Grande with Texas Cavalry and Ranger patrols running interference around them to conquer numerous major Mexican cities. Initial attacks were repulsed by dug in defenders, but the Texas Rangers showed their American brothers how to dig holes through the adobe walls and fight the Mexicans in close quarters. America performed its first major amphibious landing in Veracruz, and then marched on Mexico City where the United States Marines earned “The Halls of Montezuma” line in their anthem. In the end, America held Mexico’s capital, their northern frontier, and many of their richest cities in an iron grip. And the Texas Rangers earned the name “Los Diablos Tejanos.” The Texan Devils.