The 10th Cavalry Regiment is a unit of the United States Army. Formed as a segregated African-American unit, the 10th Cavalry was one of the original "Buffalo Soldier" regiments in the post-Civil War Regular Army. It served in combat during the Indian Wars in the western United States, the Spanish-American War in Cuba and in the Philippine-American War. The regiment was trained as a combat unit but later relegated to non-combat duty and served in that capacity in World War II until its deactivation in 1944. The 10th Cavalry was reactivated as an integrated combat unit in 1958. Portions of the regiment have served in conflicts ranging from the Vietnam War to Operation Enduring Freedom and Operation Iraqi Freedom. The current structure is by squadron, but with the 1st and 7th Squadrons recently deactivated, the 4th Squadron is the only 10th Cavalry Regiment unit in active service.  It is assigned to the 3rd Armored Brigade Combat Team of the U.S. 4th Infantry Division at Ft Carson, Colorado.. How many years was the 10th Cavalry deactivated before its reactivation in 1958?