Hi Janet: My grandmother told me, that her ancestors were taken from Guinea West Africa, as slaves and were landed on Blackistone Island, at Colton Point, on the Potomac River, in St. Mary's County, Maryland. The island is now called St. Clements Island. It was named after the white Blakistone family, many of which still reside in the Washington, D.C./ Maryland area. They own a well known florist business in Washington, D.C.. There was a Dr. R. Pinkney Blackistone Md., who lived in Wash. D.C. and some in Bethesda, Md.,Oakland, Md. and Silver Springs.
I called an African American Blackiston, today, who lives in D.C. and he says there are two families of African Americans, who are not related, as far as he knows. His family spells their name, Blackiston and the other family spells their name Blackstone. Mr. Blackiston said there are others who live in the Washington and Maryland area. Some are in the D.C. and Maryland (Prince Georges County) phone book.
I hope this gives you some leads. Lloyd