Clipped from Wikipedia: Situated somewhere in the Atlantic Ocean, Blackhawk Island is home base for the Blackhawks, a paramilitary group known to exist during World War II. The island is not listed on any navigational charts, nor is its location known to any government. Blackhawk Island housed the members of the Blackhawk Squadron, their planes, maintenance equipment, storage facilities, and more.
Toward the end of World War II, when the Blackhawks shifted their
campaign to the Pacific to fight the Japanese, a new Blackhawk Island
was located somewhere near Japan. In the post-war adventures, it seems
clear the main base was still in the Pacific, since several missions
took place on Pacific islands that were "near" Blackhawk Island. At the
same time, it was apparently close to the continental United States,
since it was a short flight from their "mainland barracks", which seemed
to be on the west coast of the the U.S., and they could respond quickly
to emergency calls which mostly came from the U.S.
Despite its apparent secrecy, the island has fallen subject to a
number of invasions, attacks and bombardments by Nazis, Japanese,
Communists, criminals, and aliens.