During a June 25, 1951, ceremony at Arnold Air Force Base, President Harry Truman draws aside the curtain to reveal a dedicatory plaque mounted to a granite rock. The ceremony was held to dedicate the Air Engineering Development Center as the Arnold Engineering Development Center in honor of Gen. Henry H. “Hap” Arnold, who had passed away before the ceremony and whose vision was instrumental in bringing the center to fruition. Pictured with Truman is Arnold’s widow, Bee. It was 70 years ago this month that Truman signed into law the bills that allowed for the establishment of AEDC. (U.S. Air Force photo)