Family history by grandson L.  P. Allen Oct 27 1911 says  William came from Ireland in 1770 and settled near Augusta (now Richmond County..

William Allen (son of William) born Nov 27, 1788

Robert Allen (son of William) born Nov 27 1792

Elizer Allen (son of William) born Nov 27 1797

Thomas Allen (son of William) born Nov 27 1801