As 1963 began, Martin Luther King, Jr., and the SCLC were coming off a campaign in Albany, Georgia, which the New York Herald Tribune called "one of the most stunning defeats of King's career." SCLC had spent over a year in Albany attempting to integrate the city's public facilities. Although the president of the Albany Movement, Dr. William Anderson, said that the campaign was "an overwhelming success, in that there was a change in the attitude of the people involved," King felt that, "we got nothing." The schools remained segregated; the city parks were closed to avoid integration; the libraries were integrated, but only after all the chairs were removed. SCLC official Andrew Young remembered King as being "very depressed."  He was looking to start another campaign, and he badly needed a victory.
Rev. Fred Shuttlesworth of Birmingham invited King and the SCLC to Birmingham, nicknamed "Bombingham" because it was the site of eighteen unsolved bombings in black neighborhoods over a six-year span and of the vicious mob attack on the Freedom Riders on Mother's Day 1961. In 1963, the city government was undergoing a major change. Voters decided to rid the city of the three-man city commission and instead elect a mayor, mostly to force Bull Connor, commissioner of public safety and the man largely responsible for the attack on the Freedom Riders, to step down. Connor ran for mayor but the voters elected the more moderate Albert Boutwell instead. The city commission, however, refused to step down, leaving Birmingham with two city governments until the courts decided which was the legitimate one.
In the midst of this change, SCLC launched "Project C" (for Confrontation). On "B Day" (for Birmingham), April 3, 1963, SCLC staged sit-ins and released a "Birmingham Manifesto," which was largely ignored, to reporters. made much of an impact.
On April 6, police arrested 45 protesters marching from Sixteenth Street Baptist Church to city hall. The next day, Palm Sunday, more people were arrested. In addition, two police dogs attacked nineteen-year-old protester Leroy Allen as a large crowd looked on. In response to the protests, Judge W.A. Jenkins, Jr., issued an order preventing 133 of the city's civil rights leaders, including King, his friend and fellow SCLC leader Ralph Abernathy, and Shuttlesworth from organizing demonstrations. But the Project C plan called for King to be arrested on Good Friday, April 12. After a few hours of debate, King told his staff, "Look, I don't know what to do. I just know that something has got to change in Birmingham. I don't know whether I can raise money to get people out of jail. I do know that I can go into jail with them."  King was arrested and put in solitary confinement. There, he read an ad in the Birmingham News, taken out by local white ministers, that called him a troublemaker. He responded to the ad, writing in the margins of the newspaper and on toilet paper. His response was eventually published as his "Letter from Birmingham Jail":
While confined here in the Birmingham City Jail, I came across your recent statement calling our present activities "unwise and untimely" . . . . Frankly I have never yet engaged in a direct action movement that was "well timed," according to the timetable of those who have not suffered unduly from the disease of segregation. For years now I have heard the word "Wait!" It rings in the ear of every Negro with a piercing familiarity. This "wait" has almost always meant "never." 
King was released on April 20. Meanwhile, SCLC organizers started to plan "D Day." Unlike the other demonstrations, all of the D Day demonstrators would be children. James Bevel explained why the SCLC turned to children as demonstrators:
Most adults have bills to pay -- house notes, rents, car notes, utility bills -- but the young people . . . are not hooked with all those responsibilities. A boy from high school has the same effect in terms of being in jail, in terms of putting pressure on the city, as his father, and yet there's no economic threat to the family, because the father is still on the job." 
On May 2, children, ranging in age from six to eighteen, gathered in Kelly Ingram Park, across the street from Sixteenth Street Baptist Church. Around 1:00, fifty teenagers left the church and headed for downtown, singing "We Shall Overcome." They were arrested and placed in police vans. Another group left the church, and they were also put in vans. Another group left, and another. Soon the police began stuffing the protesters in school buses because there were no more vans. Three hours later, there were 959 children in jail. The jails were absolutely packed.
The next day, over a thousand more children stayed out of school and went to Kelly Ingram Park. Bull Connor was determined not to let them get downtown, but he had no space left in his jails. He brought firefighters out and ordered them to turn hoses on the children. Most ran away, but one group refused to budge. The firefighters turned even more powerful hoses on them, hoses that shot streams of water strong enough to break bones. The force of the water rolled the protesters down the street. In addition, Connor had mobilized K-9 forces, who attacked protesters trying to enter the church. Pictures of the confrontation between the children and the police shocked the nation. The entire country was watching Birmingham.
The demonstrations escalated. Because the jails were filled, the police did not know what to do. Finally, the Birmingham business community, fearing damage to downtown stores, agreed to integrate lunch counters and hire more blacks, over the objections of city officials. King had gotten his much-needed victory.