David Showman lived in York Co, PA in 1781/82(PA Aarchives, volXXI pp. 433,637. He & his wife, Maria Scholl later removed to Somerset Co, PA where they both died in 1819. Their children may have been Frederick, George & Elizabeth. As a family we have no traditions about this family.
During the Civil War our branch started using the surname Sherman, cousins in Fayette Co, PA use Showman.
Thanks,
Donald