On February 24, 1863, Arizona was formally organized as a federal territory. Claimed from Mexico in the war of 1846-48, the territory had seen sparse settlement until the discovery of gold near the town of Prescott in 1863.
When it was still a part of the New Mexico Territory, Arizona had been claimed and occupied by the Confederacy. Local historians are proud to boast that the “westernmost” battle of the Civil War was fought at Picaho Pass, roughly 50 miles from Tucson.
Concluded on April 15, 1862, the battle resulted in a Union victory. Faced with another defeat near Santa Fe at around the same time, the Confederacy was forced to abandon its dream of an empire in the West. From that point forward, Arizona remained firmly in Union hands.