If you have Manx roots then name appears to be linked with Castletown
one James Chapman was arrained for murder in 18th C but turned kings evidence - see http://www.ee.surrey.ac.uk/Contrib/manx/jmmuseum/d118.htm
possibly son of Wm and Ann chapman innkeepers in C'town 1750's - see http://www.ee.surrey.ac.uk/Contrib/manx/towns/castltwn/cstl1757.htm