The operations of Chicago Helicopter Airways represent a portion of the total Federal effort within the United States on behalf of helicopter development. This effort has been an outgrowth of the interest of the Civil Aeronautics Board and the U.S. Post Office Department which has a long tradition of looking for new developments in transport and of experimenting in new ways to move mail. Post Office interest in the aeroplane was the chief stimulus to the early development of U.S. airlines and dates back to the first scheduled air mail route authorised between New York and Washington in August 1918. It was natural, then, that the Post Office Department should have interest in the helicopter as it emerged in usable form for civil use after the Second World War.