The Great Americans definitive series, a set of stamps with sixty-three designs, issued between 1980 and 1999, comprises the largest set of face different ordinary stamps issued through the beginning of the twenty-first century. Sixty-two of the stamps honor individuals and one honors a couple, Lila and DeWitt Wallace. The general public, and even many collectors, had no knowledge of most of the individuals portrayed. Many subjects appear to have been selected to satisfy various political agendas with no apparent unifying theme.
The Great Americans are characterized by their standard definitive size, simple design lines, and monochromatic colors. They offer more complicated varieties than typically found in previous definitive series. The defining characteristics of these varieties are attributed to the numerous printing presses, perforation processes and machines, paper, phosphorescent tagging, and gum utilized by the Bureau of Engraving and Printing and the several private contract security printers used to produce stamps of the series.