During the Alabama Christian Movement for Human Rights and Southern Christian Leadership Conference's Birmingham campaign (1963), police brutally attacked nonviolent demonstrators, including hundreds of schoolchildren. They used firemen with high-pressure water hoses and attack dogs, as media reported and televised race brutality to the nation and world. Among the protest leaders arrested, King was held in City Jail. A Post-Herald statement by eight white clergy criticized him for the civil disorders, which particularly put children at risk.

King answered them. He began drafting a reply in the margins of the newspaper, continued on scraps of paper “supplied by a friendly Negro trusty,” and finished “on a pad my attorneys were eventually permitted to leave me.” Writing to his critics in the New Testament tradition of the Apostle Paul, King gave biblical and philosophical reasons for why he must “carry the gospel of freedom to all communities and states.” He defended the use of nonviolence and direct action, its timing, and its call to justice. King also deplored the moral fence-sitting of “the white moderate” and commended the “still too few” antiracist whites. Finally, he expressed hope “to meet each of you ... as a fellow clergyman and a Christian brother.”