On this day, President Richard Nixon arrives in Moscow for a summit with Soviet leaders.

Although it was Nixon’s first visit to the Soviet Union as president, he had visited Moscow once before–as U.S. vice president. As Eisenhower’s vice president, Nixon made frequent official trips abroad, including a 1959 trip to Moscow to tour the Soviet capital and to attend the U.S. Trade and Cultural Fair in Sokolniki Park. Soon after Vice President Nixon arrived in July 1959, he opened an informal debate with Soviet leader Nikita Khrushchev about the merits and disadvantages of their governments’ political and economic systems. Known as the “Kitchen Debate” because of a particularly heated exchange between Khrushchev and Nixon that occurred in the kitchen of a model U.S. home at the American fair, the dialogue was a defining moment in the Cold War.

Nixon’s second visit to Moscow in May 1972, this time as president, was for a more conciliatory purpose. During a week of summit meetings with Soviet leader Leonid Brezhnev and other Soviet officials, the United States and the USSR reached a number of agreements, including one that laid the groundwork for a joint space flight in 1975. On May 26, Nixon and Brezhnev signed the Strategic Arms Limitation Treaty (SALT), the most significant of the agreements reached during the summit. The treaty limited the United States and the USSR to 200 antiballistic missiles each, which were to be divided between two defensive systems. President Nixon returned to the United States on May 30.