How did Martin Luther King Jr. Day become a federal holiday?

On the third Monday of January every year, the federal government closes up shop for a day to honor civil rights hero Martin Luther King, Jr. - who was assassinated in Memphis on April 4, 1968.

But the road to Martin Luther King, Jr. Day was fraught. It didn't become a federal holiday until 1986, nearly 20 years after it was introduced to Congress, per the King Center. Even then, it faced an upward battle for all states to recognize the holiday, only getting nationally recognized in 2000.

While the nation recognizes King as an "icon for democracy" today, in the 1960s and 1970s, he was still a...