The Reverend Martin Luther King, Jr. writes “Letter from Birmingham Jail” in April 1963 in response to being imprisoned for his efforts to desegregate Birmingham, an important, industrial Alabama city known for its repressive and regressive policies during the 1960s. King decides to write because the Birmingham campaign, King’s policies, and his very presence have been attacked in print by eight white clergymen. King never names his critics, but his letter offers a detailed renunciation of their charges that his efforts are ill-timed, misguided, and inopportune. Bringing together ideas from philosophy, history, religion, and his own experience, King defends the program of nonviolent direct action and argues powerfully for the need to end racial injustice in the United States. 

The letter falls into two main parts. In its first half, approximately the first 22 paragraphs, King rejects the criticisms lodged against him by the white clergymen, particularly their admonition to wait for a more appropriate moment to launch a campaign for racial equality, noting that action is merited based on the deliberate and ongoing lack of response to desegregation legislation. King details the principles of nonviolent direct action, exposes readers to the conditions endured by Black Americans, and defends his belief in the supremacy of moral law over an unjust legal code. Across the letter’s second half, King goes on the offensive, outlining the failings of white moderates, people who are sympathetic in the abstract but judgmental of the tactics deployed in actual campaigns, and the limitations of the white church with regard to endeavors supporting Black Americans obtaining their human rights. The two parts culminate, perhaps improbably, in a hopeful image of a clearing sky, as the dark clouds of racial prejudice finally lift. It presents a powerful argument and vision of what the United States can be. 

King takes inspiration from many different persons in the letter, including white allies, Biblical figures, and people from American history. As he explains across “Letter from Birmingham Jail,” such people understand what it means to recognize the moral imperative to fight injustice. Rather than remain trapped by an unjust legal system or by norms that insist on inequality, they realize that the law of the conscience must sometimes prevail. “Letter from Birmingham Jail” differentiates importantly between different ways of understanding what justice means, suggesting that this intellectual work is also part of any campaign for equality. Although all the work protesters must do is hard—from their careful efforts to prepare themselves for the campaign, enduring brutality and prison, suffering ongoing discrimination and humiliation—he writes in the hopes that others will join the fight. Given that he composes the letter before the Birmingham campaign’s conclusion, it can also be read as an attempt to recruit others to join him in a pacifistic but determined fight for justice and freedom for all.