The following feature is excerpted from TIME Martin Luther King, Jr.: His Life and Legacy, available at retailers and at the Time Shop

Revolutions tend to be measured in blood. From Lexington and the Bastille to the streets of Algiers, the toll on a repressed people seeking freedom is steep. But what does it take for a people to absorb degrading insults, physical attack and political repression in hopes that their oppressors will see the error in their ways? For Martin Luther King Jr., it was a dream.

Over the course of a decade, King became synonymous with nonviolent direct action as he worked to overturn systemic segregation and racism across the southern United States. The civil rights movement formed the guidebook for a new era of protest. Whether it be responding to wars or protesting an unpopular administration at home, or the “color revolutions” across Europe and elsewhere overseas, the legacy of moral victory begetting actual change has been borne out time and again. The movement’s enduring influence is a far cry from its humble beginnings.

In March 1956, 90 defendants stood in wait in an aging Greek-revival courthouse in Montgomery, Ala. They faced the same charge: an obscure, decades-old anti-union law making it a misdemeanor to plot to interfere with a company’s business “without a just cause or legal excuse.” Their offense? Boycotting the city’s buses.

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Young, old and from all walks of life—24 were clergymen—what united them was their dark skin and their act of quiet rebellion. First to face the judge was Martin Luther King Jr., 27, the youthful pastor of Dexter Avenue Baptist Church in Montgomery. Almost four months earlier, a black seamstress named Rosa Parks had sparked a boycott of the city’s privately owned bus services after she was arrested for refusing to give up her seat to a white patron. Within days, the Montgomery Improvement Association was formed to organize private carpools to compete with the buses. King, who had moved to the city only two years earlier, was quickly elected its leader.

For 381 days, thousands of black residents trudged through chilling rain and oppressive heat, ignoring buses as they passed by. They endured death threats, violence and legal prosecution. King’s home was bombed. But instead of responding in kind, the members of the movement took to the pews, praying and rallying in churches in protest of the discrimination they suffered. In the courthouse, 31 testified to the harassment they endured on the city’s segregated buses, not so much a legal strategy as a moral one. Unsurprisingly in a city whose white–supremacist “White Citizens’ Council” membership skyrocketed after the boycott, King was found guilty and jailed for two weeks. As he said later, “It was the crime of joining my people in a non-violent protest against injustice.”

The boycott ended on Dec. 20, 1956, after the Supreme Court ruled that the racial segregation of buses was unconstitutional. But the enduring victory of Montgomery belonged not to the lawyers but to King and his fellow pastors—and the tens of thousands who followed them. Their protest shone a spotlight on the absurd lengths (enforcing an arcane and rarely invoked law) to which an entrenched power would go to protect a system designed to rob citizens of their worth solely because of their skin color.

“The strong man is the man who will not hit back, who can stand up for his rights and yet not hit back,” King told thousands of Montgomery Improvement Association supporters at the city’s Holt Street Baptist Church on Nov. 14, 1956. The black citizens of Montgomery would demonstrate their humanity while victims of a broken society. Nonviolence was the “testing point” of the burgeoning civil rights movement, King explained. “If we as Negroes succumb to the temptation of using violence in our struggle, unborn generations will be the recipients of a long and bitter night of—a long and desolate night of bitterness. And our only legacy to the future will be an endless reign of meaningless chaos.”

King had made the plight of the nation’s oppressed black citizens too plain to ignore, and it was a sharp blow to the “Christian conscience” of the white South. “They’ve become tortured souls,” Baptist minister William Finlator of Raleigh, N.C., told TIME then of his colleagues. “King has been working on the guilt conscience of the South. If he can bring us to contrition, that is our hope.”

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King became the symbol of nonviolent protest that had come to the fore in Montgomery. Inundated with speaking requests and interviews, and beset by threats of violence, King become a national celebrity both for what he accomplished and how. “Our use of passive resistance in Montgomery,” King told TIME, “is not based on resistance to get rights for ourselves, but to achieve friendship with the men who are denying us our rights, and change them through friendship and a bond of Christian understanding before God.”

On Jan. 10, 1957, weeks after black residents returned to unsegregated buses in the Alabama capital, King convened a gathering at the Ebenezer Baptist Church in Atlanta, the church where his father preached and that he would later lead. He invited influential civil rights activists, like strategist Bayard Rustin and organizer Ella Baker, and prominent black ministers from across the South to discuss how to expand the nonviolent resistance movement. After weeks of discussions, they formed the Southern Christian Leadership Conference (SCLC), a confederation of civil rights groups across the South, with King at the helm, that would go on to spread his philosophy.

Central to the SCLC’s mission was the notion that the Montgomery model could be replicated across the segregated South, to strike a blow against the entire Jim Crow system, which entrenched racial division in law and practice. But it wasn’t an easy sell. As the SCLC worked to recruit black churches and ministers, the organization faced real concerns of retaliation—both physical and economic—against those who signed on. Some doubted the method of nonviolent protest, believing the courts would eventually provide for integration. Others, especially younger groups, called for more-aggressive efforts.

But by 1960, nonviolent protests were sweeping across the South. In just one week in April, hundreds of black students were arrested as young people sat in and picketed segregated stores and diners from Nashville, Tenn., to Greensboro, N.C. Yet progress was painfully slow. In Savannah, Ga., the white mayor, Lee Mingledorff, demanded that the city council outlaw unlicensed picketing. “I don’t especially care if it’s constitutional or not,” he said. There were even more arrests, but the protests tired before achieving change.

The following year’s efforts were hardly more effective. A summer of Freedom Rides—in which black and white activists would jointly challenge segregation on buses—resulted in thousands of arrests and dozens of incidents of violence against demonstrators. But Jim Crow held. Groups consisting of younger and more impatient activists, like the Student Nonviolent Coordinating Committee (SNCC) and the Congress of Racial Equality, shifted strategy, borrowing the lessons of Montgomery. In late 1961, the SNCC and the National Association for the Advancement of Colored People targeted the heavily segregated city of Albany, Ga., with boycotts and sit-ins. The SCLC and King joined the effort, and in July 1962 King was jailed.

Days later, King was quietly bailed out and ejected from prison by Albany police chief Laurie Pritchett, who had studied the nonviolence protest method and released King to undermine it. In other cities, violence by police against peaceful demonstrators brought outcry and sympathy. But Pritchett met nonviolence with nonviolence. Within weeks, the protest fizzled out. For King, Albany was largely a failure, and his takeaway was for the movement to better pick its spots.

That place was Birmingham, Ala., “probably the most thoroughly segregated city in the United States,” King would say. Racially motivated bombings against blacks had earned the city the nickname “Bombingham,” and many of its majority-black residents were denied all but the most menial jobs—if they could find work at all. Unlike in Albany, where the goal had been to desegregate the city, in Birmingham King focused on the downtown shopping district. And unlike in Albany, he had a foil of the first degree: Birmingham’s commissioner of public safety, Eugene “Bull” Connor. Connor told TIME in 1963 that the city “ain’t gonna segregate no niggers and whites together in this town.”

The tactics changed too. While there were sit-ins and kneel-ins and demonstrations, the SCLC also encouraged an economic boycott of the city. Birmingham’s economic heart, its shopping district, was crippled when black residents refused to shop in segregated stores. Boycott organizers patrolled the streets to shame black residents into toeing the line. The protests were designed to force a crisis point, and Connor only aided the effort. When business took down “Whites Only” signs, the avowed racist threatened to pull their licenses. On Good Friday, King was jailed for his 13th time for more than a week. Using the margins of scrap paper smuggled into his cell, King drafted his “Letter from Birmingham Jail,” among the clearest representations of his philosophy.

“Nonviolent direct action seeks to create such a crisis and foster such a tension that a community which has constantly refused to negotiate is forced to confront the issue,” King wrote. “It seeks so to dramatize the issue that it can no longer be ignored.”

Children provided the movement with some of its most powerful images, and the SCLC and King encouraged students to skip school to join sit-ins and marches. On May 2, the Children’s Crusade saw the arrest of hundreds of students in Birmingham, some under the age of 10, who sang and prayed as they awaited arrest. The New York Times compared the scene to a “school picnic” as they were transported to the city’s jail by every available city vehicle. Within hours, the prison was at capacity, filled with hundreds of school-age children.

Unbowed, Connor changed tactics, and the next day he deployed fire hoses and police dogs against a peaceful protest march in the downtown business district. The images, some of the most grotesque and iconic of the era, dominated nightly news broadcasts and national newspapers and magazines nationwide. In Washington, lawmakers took up the issue of civil rights legislation with renewed vigor. President John F. Kennedy said the day’s events were “so much more eloquently reported by the news camera than by any number of explanatory words,” calling the scene “shameful.”

In a paralyzed Birmingham, more than 2,000 people had been arrested, with officials turning the state fairgrounds into a makeshift holding area. The fire department bucked Connor’s orders to redeploy its hoses against demonstrators. The city’s chamber of commerce pleaded for talks, even as political leaders were steadfast in their commitment to Jim Crow. By May 8, the white business leaders had acceded to most of King’s demands, promising to desegregate diner counters, rest-rooms and water fountains within 90 days.

It was far from total victory, but King had something more important: the attention of an outraged and rapt nation. The legacy of the water cannons and dogs, of callused feet and imprisoned children, would be incarnated in the Civil Rights Act of 1964, the Voting Rights Act and the Twenty-Fourth Amendment, which banned poll taxes. Montgomery and Birmingham also formed the script for peaceably countering injustice in a nation founded on protest. From antiwar protests during Vietnam to Occupy Wall Street and beyond, King’s commitment to nonviolent protest lives on.

Imprisoned in Birmingham Jail, King wrote in praise of those nonviolently demonstrating outside “for their sublime courage, their willingness to suffer and their amazing discipline in the midst of great provocation. One day the South will recognize its real heroes.”

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