Alexander, the largest ship ever to dock in St. John's Harbour. On March 27, 1941, the United States officially signed the Lend-Lease agreement which gave possession of the site for the installation; construction work began in earnest soon afterward. The military base in St. John's was to be operated by the United States Army Air Forces (USAAF), as U.S. military interest in Newfoundland was deemed to be primarily an air-defence mission. A major United States Navy base and air station was simultaneously under construction at Naval Station Argentia, along with a USAAF base at Stephenville. Coast defence elements at Argentia were at Fort McAndrew. The harbor facilities, population base, and seat of government at St. John's precluded some form of headquarters facility for the base under construction adjacent to Quidi Vidi Lake; therefore, it was decided that Newfoundland Base Command would be established in the capital to coordinate all US military operations in Newfoundland, as well as in the Danish territory of Greenland. The new installation was to be named Fort Pepperrell, following the tradition of naming United States Army facilities, even though it was primarily to see use by the USAAF. During April and May 1941, the Newfoundland base contractor's personnel began arriving on the island, and construction was taken over by their organization. On April 15 a lease was signed with Carpasian Park Limited, for of land upon which to build Camp Alexander, a temporary tent camp named in honor of the ship USS Edmund B. Alexander, to be located on Carpasian Road. On May 20, the troops quartered aboard USAT Edmund B. Alexander began moving into their new temporary camp. The reasons behind the apparently slow pace of construction for the base was likely related to the fact that the United States did not enter the war until late 1941. Canada and Newfoundland, by contrast, were at war, along with most of the rest of the British Commonwealth. A separate series of Canada-Newfoundland defense agreements saw Canada's military activity in the country restricted to war-time conditions, and by 1940–1941, both Canada and Newfoundland were increasingly desperate to defend the territory. War-time shortages meant that the Canadian military did not build permanent military bases but did create temporary facilities to house air force and naval units at Botwood, Gander, Bell Island and St. John's. The Canadian military buildings were often erected quickly and cheaply with materials available locally.