AUDIO: “Providence” from Soundtracks 2 by De Wolfe Music Library. Composer: Paul Lawler

Sunday, March 21st, 1965. Selma, Alabama. About 8,000 people gather at Brown Chapel and begin to march from the town of Selma to the city of Montgomery, Alabama. The demonstrators are predominantly African-American and they’re marching on the capitol for one reason. Justice. They want simply to be given the right to vote. But they’re not alone in their struggle. Demonstrators of “every race, religion, and class,” representing almost every state, have come to march with their black brothers and sisters. And at the front of the march is the Reverend Dr. Martin Luther King Jr., Nobel Prize winner, preacher, and civil rights activist leading the march like Moses leading his people out of Egypt.

In the teeth of racial opposition backed by armed police and riot squads, they had tried to march twice before, but both times were met with violence by state troopers and a deputized posse. The first time—known as Bloody Sunday—the marchers were ordered to turn back but refused and, as onlookers cheered, they were met with tear gas, Billy clubs, and rubber tubing wrapped in barbed wire. The second time they were again met by a line of state troopers and ordered to turn around, and after asking for permission to pray, King led them back.

But not this time. This time President Lyndon B. Johnson, finally having seen the writing on the wall, ordered that the marchers should be protected by 2,000 National Guard troops and federal marshals. And so they marched. For five days, over a span of 53 miles, through biting cold and frequent rain, they marched. Word spread, the number of demonstrators grew, and by the time they reached the steps of the capitol in Montgomery on March 25, their numbers had swelled to at least 25,000.