The West 11th Street graveyard is all that remains of the Second Cemetery of the Spanish & Portuguese Synagogue of the Congregation Shearith Israel. Shearith Israel, the first Jewish congregation in North America, was founded in 1654; the cemetery dates to 1805.
http://en.wikipedia.org/wiki/Congregation_Shearith_Israel
http://www.tabletmag.com/jewish-news-and-politics/76248/buried