As used in subchapters II to VII of this chapter, (a) the term “persons engaged in national-defense activities” shall include (1) enlisted men in the naval or military services of the United States; (2) employees of the United States in the Departments of the Navy, Army, and Air Force assigned to duty at naval or military reservations, posts, or bases; (3) workers engaged or to be engaged in industries connected with and essential to the national defense; (4) officers of the Army, Air Force, and Marine Corps not above the grade of captain, and officers of the Navy and Coast Guard, not above the grade of lieutenant, senior grade, assigned to duty at naval or military reservations, posts, or bases, or to duty at defense industries: Provided, That any proceedings for the recovery of possession of any property or project developed or constructed under this subchapter shall be brought by the Secretary of Housing and Urban Development in the courts of the States having jurisdiction of such causes and the laws of the States shall be applicable thereto; (b) the term “Federal agency” means any executive department or office (including the President), independent establishment, commission, board, bureau, division, or office in the executive branch of the United States Government, or other agency of the United States, including corporations in which the United States owns all or a majority of the stock, directly or indirectly.