Full FAA Chronology at this link.
19410407: The War Department-sponsored Interdepartmental Air Traffic Control Board began operations on this date. The IATCB included representatives of the Army, Navy, CAA, and CAB, and became an important coordinating agency for the location of military air installations. Forerunner to the later Air Coordinating Committee (see March 27, 1945), IATCB helped evolve many of the procedures for the control and regulation of air traffic used during the war. The Board was abolished on May 31, 1946.
19610407: FAA rescinded previous orders that had authorized the establishment of field area offices in accordance with recommendations of Project Straight-Line. (See September 2,