What Do We Know About Sally Hemings?

In the Richmond Recorder in 1802, James Thomson Callendar first began to publicly allege that Thomas Jefferson kept one of his slaves as his "concubine" and fathered children with her. "The name of SALLY will walk down to posterity alongside of Mr. Jefferson's own name," Callendar wrote in one of his articles on the scandal. What is known of Sally Hemings? What can we conclude from the evidence available?

• Sally Hemings