The third group in the Famous Americans Series honors five American educators — Horace Mann, Mark Hopkins, Charles W. Eliot, Frances E. Willard, and Booker T. Washington. The issues appeared between March 14 and April 7, 1940. One of only two women celebrated in the series, Frances E. Willard served as the first dean of women of Northwestern University's Women's College. Author Louisa May Alcott was the other woman honored. The American Educators group's overarching design element is the 'Lamp of Knowledge' or 'Lamp of Learning,' an icon also used in 1962 for the 4-cent Higher Education stamp (Scott 1262).
The colors used for each denomination remained constant across all seven groups: 1-cent, green; 2-cent, red; 3-cent, purple; 5-cent, blue; and 10-cent brown. This gave rise to jokes about the USPOD's colorblindness since Mark Hopkins, former president of Williams College, appeared on the red 2-cent stamp and Charles W. Elliot, former Harvard president, appeared on the purple 3-cent. Of course, Harvard's school color is crimson (red), and Williams's school color is purple. Since all seven groups of five stamps were issued in the birth order of their honorees, the colors of these two stamps could not be changed to reflect the schools' colors.