presidential percentage than had appeared on any previous U. S. definitive issue. Release of the Liberty series began in 1954, and the set was essentially complete by 1960, but a few values were added subsequently. While the Liberty stamps were generally replaced by the Prominent Americans series, issued starting in 1965, several of its denominations remained on sale for a considerable period of time afterwards. Most notably, two coil stamps—the 2 cent Thomas Jefferson and the 25 cent Paul Revere—were repeatedly reprinted, continuing on sale well into the 1980s. Remaining stocks of the 12 cent Benjamin Harrison stamp were sold at some post offices in 1981 to meet the new postal card rate as the United States Postal Service was not able to issue a new 12 cent stamp prior to the implementation of the rate increase. Over the time span that the series was issued the technology of printing postage stamps changed. This led to many of the stamps having varieties with different papers, perforations and the addition of a phosphor coating. Thus at this more specialized level the series is rather complex. The 1/2 cent stamp was the last issued of that denomination for use as postage, although a postage due stamp of that value was issued in 1959. It was also the last appearance of Franklin on a lower value stamp in a regular series, a tradition that had been followed since 1847. In this series, two of the fractional denominations—1¼¢ and 2½¢—appeared on U. S. postage stamps for the first time. Stamps of the Liberty issue, their first day of issue sites and dates Sheet format: ½¢ Benjamin Franklin, Washington, D.C. - Oct. 20, 1955 1¢ George Washington, Chicago, IL - Aug. 26, 1954 1¼¢ Palace of the Governors, Santa Fe, NM - Jun. 17, 1960 1½¢ Mount Vernon, Mount Vernon, VA - Feb. 22, 1956 2¢ Thomas Jefferson, San Francisco, CA - Sep. 15, 1954 2½¢ Bunker Hill Monument, Boston, MA - Jun. 17, 1959 3¢ Statue of Liberty, Albany, NY - Jun. 24, 1954 4¢ Abraham Lincoln, New York, NY - Nov. 19, 1954 4½¢ The Hermitage, Hermitage, TN - Mar. 16, 1959 5¢ James Monroe, Fredericksburg, VA - Dec. 2, 1954 6¢ Theodore Roosevelt, New York, NY - Nov. 18, 1955 7¢ Woodrow Wilson, Staunton, VA - Jan. 10, 1956 8¢ Statue of Liberty - (Rotary Press-Flat Plate), Washington, D.C. - Apr. 9,