In December 2007 Rubenstein purchased the last privately owned copy of the Magna Carta at Sotheby's auction house in New York for $21.3 million. He has lent it to the National Archives in Washington, D.C. In 2011, Rubenstein gave $13.5 million to the National Archives for a new gallery and visitor's center. He has purchased rare so-called Stone copies of the Declaration of Independence, the Emancipation Proclamation, the 13th Amendment, the Abel Buell map, the Bay Psalm Book, and the Constitution and has lent these documents to the State Department, the National Archives, the National Constitution Center, the Smithsonian and Mount Vernon.