The Plan of San Diego and the Borderlands War
Near Brownsville, Texas
In January of nineteen fifteen, a document outlining a plan for armed insurrection across South Texas was found in Brownsville, Texas, in the possession of a captured courier, after it had been drafted and signed in a jail cell in Monterrey, Mexico. The Plan of San Diego called for Mexican Americans, African Americans, Native Americans, and Japanese Americans to rise together against the United States government, kill all Anglo males over sixteen, and reclaim Texas, New Mexico, Arizona, Colorado, and California for Mexico. The plan was mostly theoretical, but what followed was real.
Beginning in July of nineteen fifteen, a series of raids struck ranches, trains, and irrigation works in Cameron County and the surrounding valley. The first victim was a Tejano deputy sheriff named Pablo Falcon, shot at a dance in Brownsville in July. The raids escalated through August and September, derailing a train near Olmito, destroying irrigation pumps, and killing Anglo and Mexican Texan ranchers.
The Texas Rangers' response was indiscriminate and brutal. In the aftermath of the Olmito train derailment, Rangers and civilian allies captured ten ethnic Mexicans and executed them on the spot. Historians estimate that from nineteen fourteen to nineteen nineteen, somewhere between three hundred and five thousand ethnic Mexicans were killed in South Texas by Rangers, local law enforcement, and vigilantes.
The range of the estimate reflects how few records were kept and how little the deaths were investigated. Land transfers accelerated during the violence. Some Anglo landowners used the chaos and the threat of Ranger retaliation to pressure Tejano neighbors off their properties for far below market value.
The borderlands war of nineteen fifteen remains one of the least-taught episodes of mass violence in Texas history.
