The Nixon White House tapes are audio recordings of conversations between U.S. President Richard Nixon and Nixon administration officials, Nixon family members, and White House staff, produced between 1971 and 1973. In February 1971, a sound-activated taping system was installed in the Oval Office, including in Nixon's Wilson desk, using Sony TC-800B open-reel tape recorders to capture audio transmitted by telephone taps and concealed microphones. The system was expanded to include other rooms within the White House and Camp David. The system was turned off on July 18, 1973, two days after it became public knowledge as a result of the U.S. Senate Watergate Committee hearings. Nixon was not the first president to record his White House conversations; President Franklin D. Roosevelt recorded Oval Office press conferences for a short period in 1940. The tapes' existence came to light during the Watergate scandal of 1973 and 1974, when the system was mentioned during the televised testimony of White House aide Alexander Butterfield before the U.S. Senate Watergate Committee. Nixon's refusal of a congressional subpoena to release the tapes was the basis for an article of impeachment against Nixon, and led to his subsequent resignation on August 9, 1974. On August 19, 2013, the Nixon Library and the National Archives and Records Administration released the final 340 hours of the tapes that cover the period from April 9 through July 12, 1973. History of the Nixon White House taping system Just prior to assuming office in January 1969, President Nixon learned that his predecessor, Lyndon B. Johnson, had installed a system to record his meetings and telephone calls. According to his Chief of Staff H. R. Haldeman, Nixon ordered the system removed, but during the first two years of his presidency he came to the conclusion (after trying other means) that audio recordings were the only way to ensure a full and faithful account of conversations and decisions. At Nixon's request, Haldeman and his staff—including Deputy Assistant Alexander Butterfield—worked with the United States Secret Service to install a recording system. On February 16, 1971, a taping system was installed in two rooms in the White House, the Oval Office and the Cabinet Room. Three months later, microphones were added to President Nixon's private office in the Old Executive Office Building and the following year microphones were installed in the presidential lodge at Camp David. The system was installed and monitored by