Presidential library

In the United States, the presidential library system is a nationwide network of 13 libraries administered by the Office of Presidential Libraries, which is part of the National Archives and Records Administration (NARA). These are not libraries in the modern sense, but rather repositories for preserving and making available the papers, records, collections and other historical materials of every President of the United States since Herbert Hoover.

Although not officially sanctioned and maintained by NARA, libraries have been organized for several Presidents who preceded the official start of the Presidential Library Office.

More information, including a list of presidential archives and relevant legislation, on the Wikipedia page.