<Dd> 46 . Nebraska--April 1, 2016 </Dd> <P> Four states have not ratified the Twenty - seventh Amendment: Massachusetts, Mississippi, New York, and Pennsylvania . </P> <P> In certifying that the amendment had been duly ratified, the Archivist of the United States had acted under statutory authority granted to his office by the Congress under Title 1, section 106b of the United States Code, which states: </P> <P> Whenever official notice is received at the National Archives and Records Administration that any amendment proposed to the Constitution of the United States has been adopted, according to the provisions of the Constitution, the Archivist of the United States shall forthwith cause the amendment to be published, with his certificate, specifying the States by which the same may have been adopted, and that the same has become valid, to all intents and purposes, as a part of the Constitution of the United States . </P>

When was the most recent amendment and what was it