Crabb massacre

In 1856, Sonoran rebel general Ignacio Pesqueira, then fighting Mexico's conservative faction during the lead-up to the Reform War, invited American politician Henry A. Crabb to bring colonists to Sonora, ostensibly to help settle the northern frontier and assist against Apache raids and in the civil conflict. Crabb, a former California state senator and U.S. Army officer, accepted after connecting with Pesqueira through his Mexican wife. Although authorized to bring up to 1,000 colonists, Crabb's expedition departed San Diego in January 1857 with roughly 100 men, traveling through the Lower Colorado River region and New Mexico Territory (present-day Arizona) before heading toward Sonora via Tucson and Altar.

By the time Crabb's party reached Sonora, Pesqueira's liberal forces had already defeated the conservative governor, Manuel María Gándara, removing Crabb's original strategic rationale. Pesqueira's followers objected to accepting American armed assistance, and the decision was made to destroy Crabb's expedition. A message from Crabb asserting peaceful intent to the prefect of Altar was not acted upon in time. At Caborca, Crabb's men engaged in an eight-day skirmish with Mexican and O'odham forces, according to a contemporaneous account by George N. Cardwell. Crabb's men took refuge in an adobe building, which was set ablaze by an O'odham fighter, forcing their surrender.

Cardwell's letter states that 25 U.S. citizens died in the fighting and that the remaining 58 survivors were divided into groups of ten and executed by firing squad; other accounts describe 77 Americans killed in the massacre itself, excluding combat deaths. Cardwell's total count of American dead was 87, including Crabb. Mexican commander Hilario Gabilondo, ordered by Pesqueira to carry out executions, reportedly refused and left the scene with a 14-year-old American, Evans, who was later raised by Gabilondo and became a Mexican customs inspector. Crabb was permitted to write a letter to his wife before being executed by a 100-man firing squad; his head was subsequently severed and preserved.

Violence continued after the initial massacre. Days later, a group of Mexicans crossed into Arizona from San Juan and captured and executed four ill members of Crabb's party who had remained behind. A subsequent rescue attempt by twenty of Crabb's volunteers, led by Major R. N. Wood and Captain Granville Henderson Oury, was attacked by roughly 200 Mexican fighters but escaped back across the border after heavy fighting. A separate group of sixteen recruits, including Freeman McKinney, surrendered without resistance after crossing the border but were executed as well. Of the Americans who had taken part in the Caborca battle, accounts indicate only one or two survived. The episode provoked public anger in California and New Mexico Territory but was not pursued further. Gabilondo was later nearly lynched by a mob in Tucson but survived.