This aerial photograph of Gorham Normal School (later the University of Southern Maine’s Corthell Hall), showed "air marking." Roofs were painted in large lettering, 10 to 13 feet tall, to aid airplane navigation before widespread radio communication.

The National Advisory Committee for Aeronautics, the precursor to NASA) began a National Air Marking Program in 1926.

In 1942, after the attack on Pearl Harbor, the Civil Aeronautics Administration ordered all of the air markers within 150 feet from the U.S. coast be removed.