The story (and song) behind Martin Luther King Jr. Day

On this Martin Luther King Jr. Day, there's one man you may not remember who helped make the holiday possible: Stevie Wonder.

He helped cement Martin Luther King Jr. Day as a national holiday, but it didn't happen overnight.

Some lawmakers fought for more than a decade against Martin Luther King Jr. Day. Some said it was too expensive, others called King a communist.

Stevie Wonder spent 15 years trying to get King's birthday recognized. After a 1979 bill fell 5 votes short of passing the House of Representatives, Wonder started to rally support with a song he had written called Happy Birthday.

Wonder put Happy Birthday on his 1981 album Hotter Than July. On November 2, 1983, President Ronald Reagan signed the law making MLK day a national holiday and America celebrated its first Martin Luther King Jr. Day on January 20, 1986.

So thank you, Stevie Wonder and happy birthday, Martin Luther King, Jr.