The history of Mexican Americans, Americans of Mexican descent, largely begins after the annexation of parts of Mexico in 1848, the nearly 80,000 individuals then living in the U.S. became full U.S. citizens. Large-scale new migration augmented their numbers during the 1910s, as Mexico was torn by a high-casualty civil war. Until the 1960s, most lived within a few hundred miles of the border, although some resettled along rail lines from the Southwest to the Midwest.wer:
