Ward's first assignment was as a commander of black cavalry troops, serving with 'E' Troop of the 9th Cavalry Regiment on border patrol in the wilds of Arizona and New Mexico. He later was part of Brigadier General John J. Pershing's forces chasing Pancho Villa into Mexico in 1916. He was awarded the Mexican Service Medal for serving in the Pancho Villa Expedition. Recognizing that the horse had a limited future, Ward became interested in artillery and transferred to the Field Artillery Branch and was sent to join the 10th Field Artillery Regiment at Camp Douglas, Arizona.