Fifty years after his death, the principles and vision of Martin Luther King Jr. continue to be a guiding light for many leaders and many Americans. In a life cut far too short—he was assassinated at age 39—King left a legacy through his remarkable dedication to nonviolent protest, his clear righteousness and his powerful words. King’s “Letter from a Birmingham Jail” that criticized the pace of civil rights justice, his stirring “I Have a Dream” speech at the March on Washington, the march he led from Selma to Montgomery: these were just some of the moments and events that defined his extraordinary life. On the 50th anniversary of that fateful day in Memphis, this new TIME special edition recalls what King accomplished in his time. He lived long enough to win the Nobel Peace Prize—and to shift the course of history.