Static model of a DH-4 U.S. Air Mail plane.
In late 1918, the US Post Office obtained 100 surplus DH-4 bombers from the Army. These were rebuilt for mail service and pressed into service on the Air Mail Service's first transcontinental route from New York to San Francisco. The DH-4 continued in Post Office service until 1927, when the last airmail routes were passed to private contractors.