I Fighter Command was a United States Army Air Forces intermediate command responsible for command and control of the fighter operations within the First Air Force during World War II. It was initially established in June 1941 as the 1st Interceptor Command to provide air defense of the Northeastern United States. Following the attack on Pearl Harbor, the command's area of responsibility extended over the entire Atlantic coast and into Canada and Iceland. As the perceived threat of attack decreased, the command's responsibnility for training units and aircrews became its primary mission. The command continued its mission until March 1946, when it was inactivated. History Background GHQ Air Force (GHQ AF) had been established with two major combat functions, to maintain a striking force against long range targets, and the air defense of the United States. In the spring of 1941, the War Department established four strategic defense areas and GHQ, AF reorganized its Northeast Air District as 1st Air Force with responsibility for air defense planning and organization along the eastern seaboard. Simultaneously, an Air Defense Command was established at Mitchel Field to plan the air defense of the United States and develop air defense doctrine. 1st Air Force activated 1st Interceptor Command at Mitchel Field on 5 June 1941, under the command of Brigadier General John C. McDonnell, drawing its personnel from Air Defense Command, which inactivated three days earlier. The command's initial tactical components were the 6th and 7th Pursuit Wings Air Defense Shortly after the attack on Pearl Harbor, the command moved its headquarters to New York City. Here, as the importance of the North Atlantic supply line grew, it assumed responsibility for planning the air defense of Newfoundland and Nova Scotia. It selected radar sites in cooperation with Canadian authorities and worked to standardize aircraft warning procedures there. In June 1942, the command returned to Mitchel and would remain there until inactivated. The command dispatched the 33d Pursuit Squadron to provide air defense in Iceland in July. The command organized Detachment A to manage the 33rd, along with antiaircraft artillery and signal warning units involved in the air defense of Iceland. The command was charged with control of "active agents" for air defense in its area of responsibility, which included interceptor aircraft, antiaircraft artillery and barrage balloons. Civilian organizations provided air raid warnings and enforced blackouts and came under the authority of the Office of