While in jail, King read a statement by eight of the leading moderate white clergy in Alabama, condemning the protests and branding King an extremist. The indignant, frazzled leader poured his rejoinder onto newspaper margins and toilet tissue. The iconic document that emerged from those jottings, the "Letter from Birmingham Jail," was always more than a spirited defense of civil disobedience. It was an indictment of white indifference. "Few members of the oppressor race," King insisted, "can understand the ... passionate yearnings of the oppressed race." It was also a declaration of black self-sufficiency ("If the inexpressible cruelties of slavery could not stop us, the opposition we now face will surely fail.") and a stirring refusal of patience. "The word 'Wait!'" wrote King, "rings in the ear of every Negro with piercing familiarity." The "Letter" was radical in the scope of its rebuke. King's key targets were not the Klan and Wallace but the very core of American culture, every sort of moderate "who paternalistically believes he can set the timetable for another man's freedom."

Neither King's sacrificial act nor his roiling anger was enough to jumpstart the movement, even after he got out of jail on April 20. But in early May, the city's black youth renewed the insurgency. After singing rousing verses of "I Woke Up With My Mind Stayed on Freedom," they burst through the doors of the Sixteenth Street Baptist Church and faced down Bull Connor's dogs and fire hoses. Within days, an agreement was forged to desegregate the city. The nation had begun its lurch toward the March on Washington, King's "I Have a Dream" speech, and the Civil Rights Act of 1964.

Meanwhile, the federal court-ordered integration of the University of Alabama loomed on June 11. Governor Wallace vowed to stand in the schoolhouse door to block the mixing of races. Kennedy's speech, the one that so impressed and surprised King, came just hours after forcing Wallace to step aside. "We are confronted primarily with a moral issue," he declared. "It is as old as the scriptures and is as clear as the American Constitution." The president was finally using language the demonstrators could appreciate: "We preach freedom around the world," he said, "but are we to say to the world, and . . .to each other that this is the land of the free except for the Negroes ...?"

Throughout the speech Kennedy seemed to be channeling the "Letter from Birmingham Jail." King had invited white people to put themselves in a black person's shoes: "When you have seen vicious mobs lynch your mothers and fathers at will," or " when your first name becomes 'nigger,' your middle name becomes 'boy,' ... then you will understand why we find it difficult to wait." Kennedy, too, used the place-trading device: "If a Negro can't enjoy the full and free life which all of us want, then who among us would be content to have the color of his skin changed and stand in his place?"