Inspired by the Civil Rights movement and the Civil Rights Act of 1964, black politicians found new opportunities beginning in the 1960s. Edward Brooke of Massachusetts was elected as the first black senator to the U.S. Congress since Hiram Rhodes Revel (R-MS) served in the 41st Congress (1870). Thurgood Marshall took the bench in the United States Supreme Court in October 1967, and two major cities—Cleveland, Ohio, and Gary, Indiana—elected the first black mayors Democrats Carl Stokes and Richard Hatcher.
American Abolitionist Frederick Douglas (ca. 1817-1895) was honored on a Prominent Americans commemorative issue in 1967. Douglas was the second black citizen featured on a stamp. Scientist George Washington Carver (1864-1943) had been honored in 1948.
During this same period, four stamps and one souvenir sheet had an international theme. In 1966 Washington, D.C., hosted the Sixth International Philatelic Exhibition. A five-cent stamp and souvenir sheet were issued for SIPEX. In July 1966 Poland marked its millennium as a Christian country, and in 1967 Canada celebrated its centennial of nationhood, and Finland commemorated its fifty years of independence. The United States issued three engraved five-cent stamps for these anniversaries. The Polish and Finnish designs featured the beautiful coat-of-arms with the spread eagle and rampant lion.