On Sunday 21 March 1965, anywhere between 3,000 – 8,000 people set off from Brown Chapel, Selma, in Alabama, for a third march to Montgomery, some 54 miles away.
Unlike the previous two attempts, this time they were protected by the National Guard, ordered there by President Johnson.
Most of the participants were Black, but a few were white and from other minority groups. At the front were civil rights and religious leaders, among them Dr. King, Rev. Fred Shuttleworth, the Greek Orthodox Archbishop Iakovos, Rabbis Abraham Joshua Heschel and Maurice Davis, plus at least one nun.
The march set off along the four-lane highway until it reached Lowndes County, where it narrowed to two lanes. Under orders from a judge, only 300 marchers were allowed to continue along the narrower stretch, with the majority returning to Selma on a fleet of buses and cars.
The small contingent continued on, supplied with food along the way from local churches. Despite the temperature dropping below zero, they slept in fields along the way, though they were always encouraged and cheered on by well-wishers in the small towns through which they passed.
Lowndes County was highly symbolic for the marchers and for the voting rights cause. Despite the population being 81% African American, not a single non-white person was registered to vote. What was more insulting was the fact that the 2,240 whites registered to vote represented 118% of the adult white population. In Lowndes, like many similar counties in the South, it was common practice to retain white voters on the rolls after they died or moved away.
On the third day, many of the marchers wore kippot, Jewish skullcaps, to emulate the marching rabbis, in appreciation of Rabbi Heschel marching at the front of the crowd. The marchers called the kippot "freedom caps."
On the morning of the fourth day, 24 March, the procession crossed into Montgomery County and the highway widened again to four lanes and this allowed others to join them for final stretch.
Thousands now amassed for the final night of the march at a campsite in the City of St. Jude, a complex on the outskirts of Montgomery. There, on a makeshift stage, a "Stars for Freedom" rally was held, with singers Harry Belafonte, Tony Bennett, Frankie Laine, Sammy Davies Jr, Joan Baez and Nina Simone performing.
The excitement throughout Montgomery and even further afield was palpable on the final morning and by the time the march arrived in downtown Montgomery, for the final walk up Dexter Avenue, the numbers had swelled to at least 25,000.
On the steps of the State Capitol Building, Dr King delivered the speech which quickly became known as ‘How Long, Not Long’.
“The end we seek is a society at peace with itself, a society that can live with its conscience. ... I know you are asking today, How long will it take? I come to say to you this afternoon however difficult the moment, however frustrating the hour, it will not be long.”
Dr King then led a small delegation to the entrance to the capitol with a petition for Governor Wallace, but their passage was blocked by a line of state troopers. King was told that the governor was not in, but undeterred, they remained at the entrance until one of Wallace's secretaries appeared and took the petition.
Despite the horrific murder of Viola Liuzzo, a white mother of five from Detroit who had come to Alabama to support voting rights for African Americans – and was shot and killed by KKK members (including an FBI informant) as she was returning from ferrying marchers back to Selma from Montgomery – the march helped create an almost unstoppable sense of momentum for change.