Government-operated airmail lines were well established by 1925. But to many, it seemed advantageous to let private enterprise take over. In an effort to promote civil aviation, an Act of Congress set the rate of airmail matter on a contract basis. This issue fulfilled the rate on contract airmail, which was 10¢ per ounce up to 1,000 miles. Once the industry opened up, contracts were let out and assigned route numbers to carry the mail. Ford Motor Company was the first contractor ready to fly mail. The expansion of the contract airmail system was slow. More than six months passed before it became necessary to issue this 15¢ stamp to pay for airmail flown over 1,000 miles.