Since 1978, with the introduction of the Harriet Tubman stamp, the USPS has been honoring African Americans who have made vital contributions to the United States. The latest in the series is pioneering filmmaker Oscar Micheaux, who wrote, directed, produced, and distributed more than 40 movies during the first half of the 20th century. He thrived at a time when African-American filmmakers were rare, venues for their work were scarce, and support from the industry did not exist. The artwork is based on one of the few surviving photographs of Micheaux, a portrait that appeared in his 1913 novel, "The Conquest." BlackEnterprise.com takes a look at other African Americans who were imortalized on stamps. (Date issued: June 22, 2010)BlackEnterprise.com wants to know: Who do you think should be on the next Black Heritage stamp?The Black Heritage series has been one of the USPS's most popular ever created. When an early-2000 Internet rumor spread that the series was going to be canceled, the postal service was inundated with hundreds of protesting letters, postcards, and phone calls. Despite an official press release denying the rumor, it resurfaces every year.