The portrait of John Quincy Adams (1767-1848), the sixth U.S. president, appears on the orange 6-cent value of the 1938 Presidential Series. The likeness was taken from a bust on display in the U.S. Capitol.
The son of the second U.S. president, John Adams (who appeared on the 2-cent value of the Presidential Series), John Quincy Adams began a brilliant fifty-four-year career in public service when President George Washington appointed him minister to the Netherlands. He was at the time twenty-seven years old. A less-know fact, John Quincy Adams committed considerable energy to assuring that James Smithson's financial bequest to the United States be used as Smithson had willed—for the creation and dissemination of knowledge. The bequest served as the financial underpinning of the Smithsonian Institution.
Two varieties of the 6-cent stamp exist—a sheet stamp (issued July 28, 1938) and a horizontal (sidewise) coil (issued January 20, 1939).
The primary usage of the 6-cent stamp was for paying the six-cents-per-ounce domestic airmail rate (in effect July 1934 through March 1944 and again in January 1949 through July 1958) and two times the three-cents-per-ounce domestic first-class rate (in effect July 1932 through July 1958). The 6-cent stamp also saw a great deal of use paying the special six-cent airmail military concession rate available to those serving in World War II.