 It first formed about 200 to 250 years ago.Gun batteries were emplaced on the island to defend Chesapeake Bay in both world wars; these were part of Fort John Custis during World War II.Fisherman Island National Wildlife Refuge is located within the United States Fish and Wildlife Service's Eastern Shore of Virginia National Wildlife Refuge, and is cut in half by the presence of U.S. Highway 13 and the Chesapeake Bay Bridge Tunnel.