President Richard Nixon became the 1st sitting president to visit Soviet Union on May 22, 1972

MONROE, La. (KNOE) -On May 22, 1972, President Richard Nixon became the first sitting U.S. president to visit the Soviet Union. His arrival started a week-long summit that ended in several historic treaties and agreements.

Nixon had visited Moscow in 1959 when he was vice-president. His visit then was reportedly heated, and considered a key moment in the Cold War.

The 1972 visit was more conciliatory. Nixon met with Soviet leader Leonid Brezhnev and other Soviet officials.

Several agreements were reached. One laid the groundwork for joint space flight beginning in 1975.

On May 26, the two leaders signed the Strategic Arms Limitation Treaty, or SALT. It limited the United States and the USSR to 200 antiballistic missiles each, to be divided between two defensive systems.

Nixon returned to the United States on May 30, 1972.