Building the Halifax Dockyard, or the Royal Naval Dockyard as it was also known, began under the supervision of James Cook. He had arrived with Admiral Boscawen in preparation for the British attack on Louisbourg (see Boscawen, May 9, 1758). It was the first royal dockyard in North America, officially commissioned in 1759. The dockyard was designated a national historic site of Canada in 1923 and part of Canadian Forces Base (CFB) Halifax — the largest military base in Canada, with 7,500 military and 2,300 civilian employees.