Martin Luther King, Jr. Day is a United States federal holiday marking the birthday of Rev. Dr. Martin Luther King, Jr.. It is observed on the third Monday of January each year, which is around the time of King’s birthday, January 15. King was the chief spokesman for nonviolent activism in the civil rights movement, which successfully protested racial discrimination in federal and state law. He was assassinated by a prison escapee in 1968 on the balcony of a hotel as he went to get some fresh air before making a speech.