I had a pretty good selection today: from the Titanic to the birth of Beaudelaire, the ENIAC Project to the surrender of Lee's army at Appomattox. I chose Marian Anderson's free concert at the Lincoln Memorial.
Marian Anderson (1897-1993) was an African-American opera singer. She was the first black person to solo at the Metropolitan Opera of New York City.
The contralto was hoping to give a concert at Constitution Hall, when the DAR banned her because she was black. The First Lady, Eleanor Roosevelt (one of my favorite historic figures) was so upset by this she arranged for Ms. Anderson to give a free, open-air concert on the steps of the Lincoln Memorial on April 9, 1939. 75,000 people showed up to hear Ms. Anderson's awesome voice and millions listened by radio.
Four years after the incident, the DAR invited Ms. Anderson to sing for a Red Cross benefit. She finally sang at Constitution Hall in 1953.
There is so much more about her, so I'm including links, of course.
Afrocentric Voices: Marian Anderson
Wikipedia: Marian Anderson
Register of the Marian Anderson Papers
Marian Anderson at the Met