From Old Fort Brown Cavalry Drill Field, near this spot, was made the first flight of a U.S. Army plane to be fired upon in armed hostilities, April 20, 1915. Two Signal Corps officers, Lts. Byron Q. Jones and Thos. Milling, flew a Martin T.O. Curtiss 75 on the border to spot movements of Mexican revolutionist Pancho Villa. They reached 2,600 feet; were up 20 minutes. Though they did not cross the Rio Grande, the plane was hit by machine gun and small arms fire. Their patrols lasted 6 weeks. Planes were used more effectively in fighting against Villa in 1916.