Mississippi finally officially ratified the 13th Amendment to the United State Constitution, which banned slavery in 1865.
The state legislature unanimously voted on a resolution to ratify the amendment in 1995 and was the last state to do so. However, the resolution was never filed with the US Archivist in the Office of the Federal Register and therefore was never officially recorded.
The error came to light after University of Mississippi professor Dr. Ranjan Batra researched the 13th Amendment after seeing the film Lincoln. When he realized that Mississippi never officially ratified the amendment, he reached out to fellow Mississippi resident, Ken Sullivan, who was able to connect him to the Mississippi Secretary of State Delbert Hosemann. Hosemann filed the necessary paperwork, and the ratification of the 13th Amendment by Mississippi became official on February 7.
While Mississippi was the last state to formally ratify the 13th Amendment, Mississippi was also the last state to ratify the 19th Amendment in 1984, which granted women the right to vote.