Captain Hunter's orders were to establish a military alliance with the Pima (Akimel O'odham) and to watch for the advance of the California Volunteers.

This Union force would begin its march from Fort Yuma, California, and eventually capture Mesilla and Franklin (El Paso), Texas.

After the skirmish at Stanwix Station, the Battle of Picacho Peak, and the capture of a Union squad in the Pima villages, Colonel James Henry Carleton and his army of over 2,000 Californians occupied abandoned Fort Breckinridge to the northeast of Tucson.

On May 20, 1862, Captain Emil Fritz with his Company B, 1st California Cavalry Regiment, entered Tucson, not approaching from the west as the Confederates had expected, but from the north and east via the Cañada del Oro.

Lieutenant Tevis beat a hasty retreat to the south and then east along the old Overland Mail Route in the direction of Mesilla.

The California Volunteers secured Tucson without firing a single shot and returned the Stars-and-Stripes to the city after a Confederate occupation that had lasted only 80 days.

After the Battle of Glorieta Pass and the retreat of General Sibley's army, the Arizona Cavalry battalion was ordered to remain behind to hold on to Mesilla and the surrounding valley.

The skirmish ended with no known casualties on either side and reports indicate a Union victory due to the loss of Confederate horses and equipment at the battle, the rebels retreated from Mesilla a few days later.

Indeed, the California Column remained on guard in Arizona until relieved by the Regular Army of the United States in the spring of 1866, making them the last volunteer forces to be mustered out of Federal service in the American Civil War.