1972, Richard Nixon begins the first visit by an American President to what’s then the Soviet Union. He and Soviet leader sign Anti-Ballistic Missile Treaty, part of cold war détente between Washington and its communist rival Moscow in Beijing.

2002, a former Ku Klux Klansman becomes the third man convicted for one of the deadliest attacks during the America’s civil rights era. A jury finds Bobby Frank Cherry guilty of murder in the 1963 church bombing that killed four black girls in Birmingham, Alabama. Cherry receives life in prison and dies behind bars more than 2 years later. 1907, Laurence Olivier, actor director and producer of both stage and silver screen is born in Dorking, Surrey, England.

And 1992, “I bid you a very heartfelt good night.”

Johnny Carson hosts his last "Tonight Show" on NBC after nearly 30 years as TV’s king of late night.

Today In History, May 22nd Ed Donahue, the Associated Press.