The westernmost skirmish of the
American Civil War, which occurred at Stanwix Station, took place on March 29, 1862, when Capt.
William P. Calloway and a vanguard of 272 troops from the
California Column discovered a small detachment of Confederate Arizona Volunteers led by 2nd Lt.
John W. Swilling burning hay, which had been placed at Stanwix Station for the California Column's animals. After a brief exchange of gun fire with the much larger Union force, the Confederates retreated to
Tucson, the capital of the western district of the
Confederate Territory of Arizona. The skirmish resulted in the wounding of a German-born Union private, William Frank Semmelrogge (Semmilrogge), who subsequently recovered. There appear to have been no other casualties. The significance of the incident was twofold. First, the burning of hay, not only at Stanwix but at five other former stagecoach stations along the
Gila River east of Fort Yuma, delayed the California Column's advance to Tucson and
Mesilla, the territorial capital of Confederate Arizona. Before the Confederates evacuated Tucson, they also removed or destroyed the supplies gathered for the Union advance by
Ammi S. White at the Maricopa Villages. Secondly, and of more immediate importance, Swilling was able to reach Tucson and warn Capt.
Sherod Hunter, district military commander of western Confederate Arizona, of the approaching California Column. This led Hunter to place pickets at strategic locations, leading to the
Battle of Picacho Pass. ==Stanwix Station==