MINNEAPOLIS (AP) — Researchers believe they found the grave of a man who could be considered the first black male slave freed by Abraham Lincoln, tracking his final resting place to the cemetery of a former Minnesota psychiatric hospital. Adams said Costley's pension records show that he had been sent to an insane asylum in Rochester, but he couldn't determine where he had been buried so he enlisted the help of Rich Arpi, a staffer with the Ramsey County Historical Society who also does independent research. Arpi found the Rochester State Hospital's records for a black patient named "William H.