January 15 is the birthday of Rev. Dr. Martin Luther King, Jr. Since 1986, the third Monday in January each year has been set aside in the United States as Martin Luther King, Jr. Day.

The idea of the holiday was first brought up for vote in Congress in 1979, but the bill did not pass. A petition was circulated in the early 80’s that garnered six million signatures, putting public pressure on Congress to have another go.

From the beginning, the holiday touched off debate from state to state about whether is should and would be observed there. Arizona put it to public vote, and 76% of Arizona voters rejected it. As a result, the NFL moved the planned Super Bowl of 1993 from Arizona to California.

South Carolina held out until 2000 before making the observance an official state holiday. Up until that time, employees could choose between celebrating Martin Luther King Day or one of three Confederate holidays.

Modern social media allows people to post their thoughts on MLK Day for all to see. Some people post MLK quotes to Twitter. Some express opinions of their own.