Initially the hard-pressed governor of the area asked Crabb, who lived in Sonora, to assist him to putting down a local revolt. The government forces had gained the upper hand prior to Crabb’s departure from the USA. To avoid losing status among the people for having asked for outside support, the governor disavowed support of the Americans. Mexicans in Caborca learned of Crabb's band before it arrived on April 1, 1857.

As Crabb's men walked in disorderly fashion through a wheat field toward the village, the Mexicans opened fire with muskets and pistols. Though surprised the Americans were able to kill several defenders. The Americans fought their way across the clearing to the village. The street fighting became house to house with at least five Americans killed and fifteen wounded. The Mexican defenders withdrew to the church in the town plaza, where they hoped to hold off the Americans. The Mexicans suffered higher casualties than the Americans but they refused to surrender. Crabb then stormed the church by sending fifteen men with a keg of dynamite to try to blow down the heavy wooden door. The Mexicans mounted a fierce barrage of musket fire that killed five of the attackers but, although the dynamite exploded, it was not close enough to the door to do major damage. For six days there was a stand off. Crabb’s force became surrounded by Mexican reinforcements of both military troops and armed volunteers arrived to surround the American positions.

By April 6, the last day of major combat, more than 1,500 defenders with Papago Indian allies had the Crabb party under siege. The Indians fired a flaming arrow onto the thatched roof of the filibuster's stronghold. The combat of that day resulted in several of his men being wounded. Crabb’s survivors surrendered and were executed.

Later, the Mexicans encountered two more groups trying to reinforce Crabb. One was the Tucson Valley Company. Under the command of Major Wood and Captain Oury, they were about fifteen miles north of Caborca when the Mexicans intercepted them. Captain Moreno attacked vigorously, but the Americans used the confusion to flee toward the United States. A second group of sixteen more filibusters were captured by a group of Mexican soldiers who had been at Dunbar's store and were shot.

Early Filibuster Operations in America

Introduction
Filibuster Battles in the Texas Region
The Crabb Venture into Mexico 1857