"Can you believe that White man not only stepped up to the plate, he hit it over the fence!" That was Martin Luther King, Jr.'s private verdict on President John F. Kennedy's famous Civil Rights Address, delivered fifty years ago on June 11, 1963.

If King's elation made sense, so did his incredulity. Kennedy had hardly been a beacon of moral resolve on civil rights. It required the Birmingham civil rights movement–and the tough-minded theory of social change that King spelled out in the "Letter from Birmingham Jail" to provoke his speech into being. And once pushed into taking a stand with the address, Kennedy and his speechwriter Theodore Sorensen filled it with rhetoric often remarkably similar to King's. Though the address came, ostensibly, in response to a different event — the fight over the integration at the University of Alabama — it was full of echoes of "Letter from Birmingham Jail." In a powerful sense, King and the movement were the authors of the president's oratory.

The speech was a dramatic moment in a season jammed with dramatic events, as America staggered toward non-racial democracy. In his fiery inaugural speech in January of 1963, the new governor of Alabama, George Wallace had pledged, "segregation now, segregation tomorrow, segregation forever." In defiance of Wallace, King and the local movement launched civil rights protests in April in the furiously racist city of Birmingham. With the movement faltering, King decided to violate an injunction banning protests of any sort, and was, as a result, jailed on Good Friday, April 12.

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."