Subject to the provisions of Sections 207 to 233, inclusive, and of subsection B of Section 245, “employment” means any service performed prior to July 1, 1940, which was employment as defined in this Act prior to that date, and any service after June 30, 1940, performed by an individual for an employing unit, including service in interstate commerce and service on land which is owned, held or possessed by the United States, and including all services performed by an officer of a business corporation, without regard to whether such services are executive, managerial, or manual in nature, and without regard to whether such officer is or is not a stockholder or a member of the board of directors of the corporation.