Domestic airmail is a relatively recent addition to the mail services. It is also the fastest growing.

The first airmail rate was established in May 1918 at 24 cents an ounce including special delivery. By November of the same year the rate was reduced to 6 cents an ounce without the provision for special delivery. The many changes in postal rates for airmail during the period from the inauguration of the service to 1928 reflected the rapidly changing conditions that surrounded the phenomenal development of transportation by air. By 1928, however, the rates took on a more stable pattern, as shown in table III. Since that time there has remained a uniform ounce basis with a rate range from 5 to 8 cents.

The public demand for extension of air delivery led to the addition of two new services in the latter 1940's: Air parcel post service beginning in September 1948, and airmail postal and post card service in January 1949.

Airmail has played an important part in the development of commercial aviation. The funds received by airlines for carrying mail were frequently their most important source of revenue. In fact, the first commercial use of the airplane as a means of conveyance was to carry the mail.

The publicity given to the first airmail flights and to other aviation mile-stones associated with the mails focused the public^'s attention on the air-plane as a practical transportation medium. The Collier Trophy was awarded to the Airmail Service in 1923 and 1924. In 1924 the first mail was flown successfully to Alaska. In 1931 Congress authorized the award of an airmail flyer's medal of honor. These and other events were important factors which led to public trust in the safety of air flight and to acceptance of the convenience of air travel.