Americans on Monday will honor the legacy of Martin Luther King Jr., the iconic civil rights leader slain in 1968, with gatherings, parades and community service. Martin Luther King Jr. Day is observed on the third Monday in January each year, around the time of King’s Jan. 15 birthday. It’s one of America’s largest days of community service. Not many are familiar with how the day became a holiday. Just days after King’s assassination, plans were underway to designate a national holiday to honor Martin Luther King. But it took more than a decade, the help of a hit Stevie Wonder song, and pressure from King’s widow, Coretta King Scott, to make the holiday a reality. The first national Martin Luther King Jr. holiday was observed in 1986.