The recordings cap the release by the National Archives and Records Administration of 3,000 hours of tapes Nixon recorded between February 1971 and July 1973. The final installment covers the tumultuous three months when the Watergate political scandal that would force Nixon's resignation was closing in.
Still, he moved ahead with Soviet peace talks and a thawing relationship with China.
The recordings cover April 9, 1973, to July 12, 1973, the day before the existence of the covert recording system was revealed to a Senate committee.
Another 700 hours of Nixon tapes remain classified or restricted and haven't been released because of national security and privacy concerns.
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Previous tape releases show the president as a paranoid man. Tapes released in 2009 show, in particular, his obsession with the Kennedy family. He ordered surveillance of Ted Kennedy in hopes of catching him in an affair.
Today's release promises to be equally revealing, with conversations between Nixon and longtime diplomat Henry Kissinger, three future presidents and Brazilian soccer superstar Pele.
The meeting was a follow-up to Nixon's visit to the Kremlin the year before and was the first attempt at US-hosted peace talks with the Soviets in six years.
Faced with impeachment and a possible criminal indictment, Nixon resigned on August 9, 1974, a little more than a year after the tapes end.