This map depicts the corridor for flight navigation between Chicago, Illinois, and St. Louis, Missouri, including major urban areas, roads,... Show moreThis map depicts the corridor for flight navigation between Chicago, Illinois, and St. Louis, Missouri, including major urban areas, roads, railroads, etc., and the location of airfields, and navigation beacons. It was apparently produced by and for Information Division, the Office Chief of Air Corps at the Engineer Reproduction Plant, U. S. Army, Washington, D.C. in 1928 and revised in June 1932. Show less