The Battle of Picacho Pass, also known as the Battle of Picacho Peak, was an engagement of the American Civil War on April 15, 1862. The action occurred around Picacho Peak, northwest of Tucson, Arizona. It was fought between a Union cavalry patrol from California and a party of Confederate pickets from Tucson, and marks the westernmost battle of the American Civil War involving fatalities (though a skirmish known as the Battle of Stanwix Station was 40 miles further west and 80 miles from the California border in the direction of Fort Yuma). Background After a Confederate force of about 120 cavalrymen arrived at Tucson from Texas on February 28, 1862, they proclaimed Tucson the capital of the western district of the Confederate Arizona Territory, which comprised what is now southern Arizona and southern New Mexico. Mesilla, near Las Cruces, was declared the territorial capital and seat of the eastern district of the territory. The property of Tucson Unionists was confiscated and they were jailed or driven out of town. Confederates hoped a flood of sympathizers in southern California would join them and give the Confederacy an outlet on the Pacific Ocean, but this never happened. California Unionists were eager to prevent this, and 2,000 Union volunteers from California, known as the California Column and led by Colonel James Henry Carleton, moved east to Fort Yuma, California, and by May 1862 had driven the small Confederate force back into Texas. Like most of the Civil War era engagements in Arizona (Dragoon Springs, Stanwix Station and Apache Pass) Picacho Pass occurred near remount stations along the former Butterfield Overland Stagecoach route, which opened in 1859 and ceased operations when the war began. This skirmish occurred about a mile northwest of Picacho Pass Station. Battle Twelve Union cavalry troopers and one scout (reported to be mountain man Pauline Weaver but in reality Tucson resident John W. Jones), commanded by Lieutenant James Barrett of the 1st California Cavalry, were conducting a sweep of the Picacho Peak area, looking for Confederates reported to be nearby. The Arizona Confederates were commanded by Sergeant Henry Holmes. Barrett was under orders not to engage them, but to wait for the main column to come up. However, "Lt. Barrett acting alone rather than in concert, surprised the Rebels and should have captured them without firing a shot, if the thing had been conducted properly." Instead, in midafternoon the