The U.S. Supreme Court, in Smith v. Allwright, struck down a Democratic Party of Texas rule that allowed only White voters to participate in Democratic primaries.

1948

President Harry S. Truman signed the Marshall Plan to help European allies rebuild after World War II and resist communism.

1968

Civil rights leader Martin Luther King Jr. delivered what turned out to be his final speech in Memphis, Tennessee.

The first handheld portable telephone was demonstrated for reporters on a New York City street as Motorola executive Martin Cooper called Joel S. Engel of Bell Labs.