Henry Hudson discovered Delaware Bay.
Richard Wagner's opera, Lohengrin, premiered at Weimar, Germany.
The first commercial to be broadcast on radio aired on station WEAF in New York City. The ten minute advertisement for the Queensboro Realty Company cost $100.
Emmett Till, a black teenager from Chicago, was abducted and by white men after he supposedly whistled at a white woman in Mississippi. The case was reopened in 2005.
Dr. Martin Luther King, Jr. gave his famous "I Have a Dream" speech at the Lincoln Memorial to civil rights demonstrators.
Anti-Vietnam war protesters and police clashed in the streets of Chicago while the Democratic National Convention nominated Hubert H. Humphrey for president.
The Centers for Disease Control announced a medical task force had been formed to look into the incidence of Kaposi's sarcoma and pneumocystis in homosexual men. AIDS was later found to be the cause.