N.H. Rev. Stat. § 484:2
The said agreement or compact when ratified by the legislatures of each of said states and approved by the Congress of the United States, shall thereupon become operative and effective. The governor is authorized and directed forthwith to notify the governors, respectively, of the said states and the President of the United States, that the state of New Hampshire on its part has approved and ratified said compact or agreement. Upon its execution in quintuplicate by the commissioners or representatives of each of said states as previously stated, a duly executed original of the compact shall be filed in the office of the secretary of state of the state of New Hampshire, together with the original notice of ratification received from the governors of the remaining signatory states, and such notice, if any, as may be received from the President or the Congress of the United States, signifying the approval of such Congress to the compact.
RSA 484:2
1989, 339:1, eff. Jan. 1, 1990.