In April 1963, Martin Luther King Jr. sat in a prison cell in Birmingham, Alabama, jailed for his part in nonviolent demonstrations against segregation. King’s moment of glory, his “I Have a Dream” speech in Washington, was four months in the future — Aug. 28, 1963 — at this point still just a literal dream.

King was greatly stirred when eight white Southern religious leaders issued a statement criticizing his civil disobedience campaign in Birmingham. They called him an outsider. They accused him of stirring up trouble.

Obviously, the 33-year-old King did not see himself that way. He saw himself as a revolutionary — and a leader. So did his classmates at the racially integrated Crozer Theological Seminary in Chester, Pa., who had elected him class president. So did the faculty, who had awarded him a fellowship to Boston University for his Ph.D. studies.

So as King sat in that Birmingham jail cell, writing out a longhand reply to those Southern white preachers, he did not intend it as a rebuke to an opposition. Rather, King wrote respectfully to Christian colleagues and brothers to explain how his intents and actions were consistent with their doctrine and beliefs. “I feel that you are men of genuine good will and your criticisms are sincerely set forth,” he writes,“I would like to answer your statement in what I hope will be patient and reasonable terms. His tone is respectful but not defensive. He is an equal.

Responding to each allegation, he notes that academic training and church affiliation endow him with identity, authority and security, and that church leaders invited him to confront injustice in Birmingham.

“Injustice anywhere is a threat to justice everywhere. We are caught in an inescapable network of mutuality, tied in a single garment of destiny,” King writes. “Whatever affects one directly affects all indirectly. Neveragain can we afford to live with the narrow, provincial ‘outside agitator’ idea. Anyone who lives inside the United States can never be considered an outsider.”

Throughout King’s letter shines his unflinching devotion to the law, his respect for the United States Constitution and reverence for the Pledge of Allegiance.

“I started thinking about the fact that I stand in the middle of two opposing forces in the Negro community. One is a force of complacency ... a result of long years of oppression, have been so completely drained of self-respect and a sense of ‘somebodyness’ that they have adjusted to segregation. ... The other force is one ofbitterness and hatred and comes perilously close to advocating violence. It is expressed in the various black nationalist groups that are springing up over the nation, the largest and best known being Elijah Muhammad’s Muslim movement. This movement isnourished by the contemporary frustration over the continued existence of racial discrimination. It is made up of people who have lost faith in America, who have absolutely repudiated Christianity, and who have concluded that the white man is an incurable devil.

“I have tried to stand between these two forces, saying that we need not follow the do-nothingism of the complacent or thehatred and despair of the black nationalist. There is a more excellent way, of love and nonviolent protest.”

This Martin Luther King Day, let’s look past the fruit of that colossal event. Instead, go back to the spring of that year and consider the seeds that were sown, the spring rains that sustained it, and the roots of idealism that sank deep into the rich soil of American liberty.