US Code
CHAPTER 2— ACTS AND RESOLUTIONS; FORMALITIES OF ENACTMENT; REPEALS; SEALING OF INSTRUMENTS
§ 106a. Promulgation of laws

Whenever a bill, order, resolution, or vote of the Senate and House of Representatives, having been approved by the President, or not having been returned by him with his objections, becomes a law or takes effect, it shall forthwith be received by the Archivist of the United States from the President; and whenever a bill, order, resolution, or vote is returned by the President with his objections, and, on being reconsidered, is agreed to be passed, and is approved by two-thirds of both Houses of Congress, and thereby becomes a law or takes effect, it shall be received by the Archivist of the United States from the President of the Senate, or Speaker of the House of Representatives in whichsoever House it shall last have been so approved, and he shall carefully preserve the originals.