USPS begins Black Heritage series
February 1, 1978
USPS begins Black Heritage series.
The USPS began the Black Heritage series on February 1, 1978, and Harriet Tubman was the first black woman, indeed, the first black person ever, to appear on a US postage stamp.
http://suite101.com/article/usps-black-heritage-stampts--harriet-tubman-a264839