There is established in the Smithsonian Institution a bureau, which shall be directed by a board to be known as the Trustees of the National Gallery of Art, whose duty it shall be to maintain and administer the National Gallery of Art and site thereof and to execute such other functions as are vested in the board by this subchapter. The board shall be composed as follows: The Chief Justice of the United States, the Secretary of State, the Secretary of the Treasury, and the Secretary of the Smithsonian Institution, ex officio; and five general trustees who shall be citizens of the United States, to be chosen as hereinafter provided. No officer or employee of the Federal Government shall be eligible to be chosen as a general trustee.

The general trustees first taking office shall be chosen by the Board of Regents of the Smithsonian Institution, subject to the approval of the donor, and shall have terms expiring one each on July 1 of 1939, 1941, 1943, 1945, and 1947, as designated by the Board of Regents. A successor shall be chosen by a majority vote of the general trustees and shall have a term expiring ten years from the date of the expiration of the term for which his predecessor was chosen, except that a successor chosen to fill a vacancy occurring prior to the expiration of such term shall be chosen only for the remainder of such term.