Somerset Island lies between the Main Island and the old Admiralty and War Department lands on Watford Island, Boaz Island, and Ireland Island. Boaz and Watford Islands from the 1860s housed the headquarters, main barracks, station hospital, and other facilities of the Western District of the garrison of Bermuda (the Command Headquarters was at Prospect Camp in the Central District, and the Eastern District was controlled from the old headquarters at St. George's Garrison). Ireland Island housed the Royal Naval Dockyard and main base of the North America and West Indies Station of the Royal Navy. The overlarge naval and military establishment at Bermuda in the Nineteenth Century and the first half of the Twentieth Century was due to the colony's role as an Imperial fortress, the lynchpin of Britain's supremacy in the western Atlantic Ocean and (after the completion of the Panama canal and the establishment of alliance, amity, and common interests with the United States of America from the First World War, onwards) the Eastern Pacific Ocean, and upon the coast of America (as had been demonstrated during the American War of 1812, when the blockade of the Atlantic seaboard of the United States by the squadron of the then-"North America Station" of the Royal Navy had been orchestrated from Bermuda, with military forces from Bermuda working with the squadron in a succession of amphibious operations, including the Battle of Craney Island, culminating in the 1814 Chesapeake campaign that included Battle of Bladensburg, capturing and burning Washington, DC, and raiding Alexandria, Virginia),