Entire series of United States stamp issues were designed by Houston, including the Washington-Franklins and the Regular Issues of 1922. Huston often used paintings and sculptures of famous American artists like Gilbert Stuart as models for his stamp designs. One of the postage issues Huston is most noted for is the 24 cent Curtis Jenny airmail stamp of 1918, whose image became famous when the biplane was printed upside down. In another aeronautical design, six years earlier Huston had pictured an airplane on the 20 cent parcel post issue. This was the first postage stamp in the world to depict such a machine.
memorial issue of 1923 Huston is also noted for designing the Warren G. Harding memorial issue of 1923, which he designed in one day using a modified version of the Fourth Bureau Issue frame and a copperplate etching of the late Harding. The prompt and speedy production of the Harding memorial issue was the result of overwhelming public pressure and the stamp was issued only a month after the late President Harding's passing, a record for U.S. postal history that has never since been broken. The first Huston design issued by the Post Office was the 2-cent Washington "shield" stamp offered in November 1903. This was a replacement for the much criticized Washington "flag" stamp from the definitive series of 1902, designed by Raymond Ostrander Smith. The public welcomed the replacement, and the Louisiana Purchase Exposition commemoratives, a series of five stamps designed by Huston, went on sale the following year. Huston designed the long running Washington-Franklin Issues, a series of definitive stamps bearing the profiles of George Washington and Benjamin Franklin. These issues remained in print longer than any other series of stamps to date. Houston was also the principal designer of the US Regular Issues of 1922-1931. Dozens of United States postage stamp designs were created by Huston. Besides designing the world-famous Curtis Jennyairmail stamp, Huston is credited for designing the Founding of Jamestown issues, the Abraham Lincoln and Ulysses S. Grant regular issues of the 1920s, the Huguenot Walloon commemorative issues of 1924, The Pilgrim Tercentenary of 1920 and the American Indian regular issue of 1923. The Washington-Franklin Issues and his seven contributions to the 1932 Washington Bicentennial Issue are among his more famous designs.
