The 6-cent South Carolina Tricentennial commemorative stamp was first placed on sale at Charleston, South Carolina, on September 12, 1970.
The stamp marks the 300th anniversary of the founding of Charles Town (Charleston), which was named after King Charles II of England, as the first colonial city in South Carolina.
Designed by George Samerjan, the stamp was issued in panes of fifty, with an initial printing of 130 million.
Postal Bulletin (August 6, 1970).
The Timepage. "13 Originals: Founding the American Colonies." http://www.timepage.org/spl/13colony.html