Between 1915 and 1918, vigilantes, local law officers and Texas Rangers executed, without due process, unknown thousands of Mexicans for their alleged role in a revolutionary uprising known as the Plan de San Diego. White fears of Mexican revolutionary violence exploded in July and August 1915, after Mexican raiders committed a series of assaults on the economic infrastructure of the Lower Rio Grande Valley in resistance to white dominance. The raids unleashed a bloody wave of retaliatory action amid a climate of intense paranoia.

While there are certainly instances in the history of the American South where law officers colluded in mob action, the level of engagement by local and state authorities in the reaction to the Plan de San Diego was remarkable. The lynchings persisted into the 1920s, eventually declining largely because of pressure from the Mexican government.

Historians have often ascribed to the South a distinctiveness that has set it apart from the rest of the United States. In so doing, they have created the impression of a peculiarly benighted region plagued by unparalleled levels of racial violence. The story of mob violence against Mexicans in the Southwest compels us to rethink the history of lynching.