The Story of the U.S. Air Force � 1907-1942 - This DVD traces the development of the United States Air Force (USAF) in the 20th century. From uncer-tain beginnings as the Army Air Force in 1907, the USAF has grown to become the greatest instrument for projecting military power ever devised. In this DVD, we follow the evolution of U.S. air power from its birth in 1907 to its emergence during World War II as the greatest air force ever conceived. During this thirty-five year period, aviation technology grew by leaps and bounds, evolving from the simple bi-planes of the Wright Brothers to the giant bombers and fighter aircraft that would come to play a critical role in the conduct of the war.