WASHINGTON (CNN) - It's been more than 60 years since someone tore out the most important page of a handwritten letter from President Lincoln - but the National Archives on Thursday will officially regain custody of that missing document.
The letter, written in 1863, has been circulating among collectors in the time since an unidentified person stripped the central page from a volume held by the U.S. Treasury.
The other half of the letter remained in the bound volume, but scholars and researchers had no idea where the second page had gone. The donor is now giving that page to the National Archives to complete the document. The agency will not say whether the donor will disclose details of the path it has taken since the 1940s.
The agency is also keeping secret what the letter is about until Thursday, when officials plan to display the documents, tell the story, and introduce the donor at a news conference at the National Archives in Washington.