Post-presidency
After Nixon's resignation, the federal government took control of all of his presidential records, including the tapes, in the Presidential Recordings and Materials Preservation Act of 1974. From the time that the federal government seized his records until his death, Nixon was locked in frequent legal battles over control of the tapes; Nixon argued that the act was unconstitutional in that it violated the Constitutional principles of separation of powers and executive privilege, and infringed on his personal privacy rights and First Amendment right of association.
The legal squabbling would continue for 25 years, past Nixon's death. He initially lost several cases, but the courts ruled in 1998 that some 820 hours and 42 million papers and documents were his personal private property and had to be returned to his estate.
On July 11, 2007, the National Archives were given official control of the previously privately-operated Richard Nixon Library & Birthplace in Yorba Linda, California. The newly renamed facility, the Richard Nixon Presidential Library and Museum, now houses the tapes and releases additional tapes to the public periodically.
Read more about this topic: Nixon White House Tapes