Alexander is probably Robert Alexander, son of Col. Gerard Alexander and his wife Mary Dent Alexander. It is probable that GW sent some of his mares to Alexander’s nearby plantation to be bred, possibly to an English stallion which he had previously sold to Alexander (General Ledger A description begins General Ledger A, 1750–1772. Library of Congress, George Washington Papers, Series 5, Financial Papers. description ends , folio 96).