Date: January 15, 1981

If you've ever been to a black birthday party, you've heard "Happy Birthday to ya'" sang in place of the more ubiquitous "Happy Birthday, dear Blah Blah" song, complete with two-step and soul-clap for good measure. The song actually originated during a campaign to declare Martin Luther King Jr.'s birthday a U.S. holiday. Stevie Wonder wrote the original in 1981 to raise awareness for the cause, and the full track finds him expressing his disbelief that anyone would oppose celebrating a day in MLK's honor. He held a massive concert/rally on the Washington Mall that January that featured Gil Scott Heron, Diana Ross, Jesse Jackson and several other key black figures, and toured throughout the South performing the song and spreading awareness of the cause. Eventually his message got through, and in 1983 Ronald Reagan signed the holiday into law.