By the end of the 1930s, legislation had stripped all remnants of control of airmail service from the Post Office Department. The branch of the federal government that paved the way for commercial aviation in the United States was no longer in control. The postal service continued to award contracts to bidders for carrying airmail, but their influence over the industry had all but vanished. U.S. aviation companies finally were in control of their own destinies.
On May 20, 1939, Pan American Airways completed the first transatlantic scheduled airline service, using a Boeing 314 Yankee Clipper to carry passengers and mail from New York to Portugal. Two decades later, on October 4, 1958 a jet carried mail across the Atlantic Ocean for the first time. Mail traveled on this date between London and New York City.
By 1975, carrying mail by air, once a whimsical fad, had become such a fundamental part of American life and the postal service's transportation plan that by October 11, all U.S. first class mail was deemed to be carried by air without requiring an additional airmail fee.