On Peaceful Mission -- Four squadrons of the ninth bombardment group, two motored ships of the Douglas B-18 type from Mitchell Field, New York, drone high over gravelly point on the Potomac during an air show highlighting the dedication by president Roosevelt Sept. 28 of the $12,500,000 Washington, D.C. Airport. In a speech Roosevelt said the united states was building a defense Capable of overcoming any attack. September 28, 1940. (Photo by Associated Press Photo).