The Raid on San Ygnacio refers to a battle fought on June 15, 1916 between the United States Army and Mexican raiders near the border town of San Ygnacio, Texas. Three different Mexican factions were known to have launched raids into Texas at the time but most of the evidence suggests that either Seditionists or Carrancistas were responsible for the incursion. Four American soldiers were killed during the battle, along with at least six of the raiders, and the resulting American punitive expedition further strained the already hostile relationship between the Mexican and United States governments.