Civil rights leader Martin Luther King, Jr. waves to supporters in 1963 on the Mall in Washington. Monday is MLK Day. Getty Images

Monday is devoted to Martin Luther King Jr., a civil rights pioneer known for his 1963 “I Have A Dream” speech. The federal holiday, which is observed every year on the third Monday in January, honors the nonviolent activist. Thousands of Americans remember watching “Our Friend, Martin” in grade school, but that's where many people's knowledge ends.

Take some time Monday to learn more about King's life and legacy, which persists today even though he was assassinated in 1968. Here are 15 little-known facts about King, collected from the King Center, CNN and the History Channel:

1. He was born Jan. 15, 1929, as Michael King. But his dad later renamed him after Martin Luther, the monk who started the Protestant Reformation in 1517.

2. King wanted to be a pastor and attended Crozer Theological Seminary in Chester, Pennsylvania.

3. He went to college at age 15 and became a minister at 19. He had his doctorate degree by age 25.

4. King got involved in protesting in 1955 when a group of leaders created the Montgomery Improvement Association to start a bus boycott in support of Rosa Parks. King became its spokesman.

5. Over the course of King's 39-year life, police arrested him 30 times. One of his arrests was for driving 30 mph in a 25 mph zone with three friends in the car. The officers put him in jail.

6. King survived his first assassination attempt. Izola Ware Curry, who the Huffington Post reported was mentally ill, thought King and the NAACP were tracking her in the 1950s. At a New York City book signing in 1958, Curry walked up to King and stabbed him with a letter opener.

7. King went to the hospital but publicly forgave Curry 10 days later. “I feel no ill-will toward Mrs. Izola Curry and know that thoughtful people will do all in their power to see that she gets the help she apparently needs if she is to become a free and constructive member of society,” he said at a news conference.

8. Curry died last year at age 98.

9. King said he was “deeply influenced” by Gandhi’s method of nonviolent resistance. “He was able to mobilize and galvanize more people in his lifetime than any other person in the history of this world,” King once said.

10. King was the youngest recipient of the Nobel Peace Prize when he won at age 35. That record was broken in 2014 by 17-year-old activist Malala Yousafzai.

11. King was killed by a single bullet fired at a Memphis hotel by James Earl Ray on April 4, 1968.

12. His last words were to musician Ben Branch: “Ben, make sure you play ‘Take My Hand, Precious Lord’ in the meeting tonight. Play it real pretty.”

13. People across the country rioted after his assassination. Police reportedly arrested about 27,000 people in the month following King’s death.

14. A lawmaker proposed designating a federal holiday for King four days after his death in 1968. The bill didn't become law until 1983. Not all 50 states recognized MLK Day until 2000.

15. Ray, who confessed to killing King, escaped prison for three days in 1977. He died in 1998.