The Callahan Expedition occurred in October 1855, when James Hughes Callahan led a force of 111 men into Mexico near Piedras Negras, Coahuila.
The announced purpose of the unauthorized invasion was to punish Lipan Apache Indians who reportedly had raided along the Texas frontier during the summer and fall of 1855, then returned to Mexico, where they were protected by the authorities.
In fact, the expedition likely was an attempt by Texas slaveholders to regain fugitive slaves who had fled to northern Mexico and to discourage Mexican authorities from permitting runaway slaves to settle in their midst. That summer the slaveowners sent an emissary to talk with Governor Santiago Vidaurri of Nuevo León y Coahuila, but Vidaurri rebuffed the agent and warned his military commanders on the frontier to be ready for an invasion.
Callahan crossed the Rio Grande on October 1. On October 3, the Texans encountered a Mexican detachment at the Río Escondido, where a skirmish ensued. The next morning, Callahan retreated to Piedras Negras and took possession of the town. As the Mexican force approached the town, Callahan ordered his men to set fire to homes to cover their retreat. On October 6, American forces across the river at Fort Duncan provided covering fire for the Texans as they retreated across the river.
The claims originating with this invasion of Mexico were not officially settled until 1876, when the Claims Commission of 1868 finished its work. The commission awarded approximately 150 Mexican citizens a total of $50,000 in damages.