Martin Luther King, Jr. published Why We Can't Wait in 1964, shortly after the momentous events in Birmingham, Alabama had helped garner national attention on the movement for civil rights in the South. Essentially, King writes to explain why the events of 1963 occurred and to articulate the reasons for the urgency of the Civil Rights Movement at the time. In the first chapter, entitled "The Negro Revolution—Why 1963," he writes that many African American leaders had become frustrated with the halting progress toward equality by that point. In particular, many were disillusioned with the federal government after it had generally failed to enforce the Supreme Court's 1954 ruling in Brown v. Board of Education. Many in 1963 saw President John F. Kennedy as insufficiently committed to civil rights. Looking abroad to Africa, where decolonization movements led to freedom for African people, they became increasingly restive in their own country. Finally, 1963 was the centennial of emancipation, and African Americans could see that they had yet to achieve equality. All of these factors, King argues, made 1963 a watershed year for civil rights.

In the second chapter, called "The Sword that Heals," King outlines the tactic of nonviolent civil disobedience and direct action that proved successful in Birmingham (but not in Albany, Georgia earlier in the year.) In chapter three, he describes "Bull Connor's Birmingham," outlining the power structure of this "most segregated city in America" (48). This structure included a sort of parallel organization of civil rights workers that became the foundation for the movement in Birmingham. This theme is continued in chapter four, "New Day in Birmingham," which relates how civil rights leaders planned a movement against the city's segregated downtown, a "direct action" exercise that, King and other leaders knew, would elicit a violent response that would be televised nationally. It was during this campaign that King was arrested, and his famous "Letter from Birmingham Jail" was written during this time. This letter forms chapter five of the book, and it is a response to several local clergymen who urged King to desist from his course of civil disobedience. His response was to castigate Southern moderates who refused to condemn the evils of segregation. He also explains his view of citizenship, one which makes "injustice anywhere... a threat to justice everywhere" (87). Moreover, he explains the purpose of direct action, that is, to provoke a crisis that will force those in power to negotiate with protestors to end the injustice in Birmingham.

In "Black and White Together," King describes the campaign to put pressure on Birmingham's leaders, one that culminated with the so-called "Children's March" that ended with violence against young protestors. Chapter seven, "The Summer of Our Discontent," reveals that after the Birmingham protests, discrimination continued in Birmingham. African American children had been murdered, including the bombing of the 16th Street Baptist Church in which four African American girls were killed. The chapter concludes on a high note, pointing to the possibilities raised by the March on Washington in September of that year. In the final chapter, "The Days to Come," he anticipates how the movement will go forward in the years to come. He is insistent that an end to Jim Crow will not bring about an end to injustice in the United States and begins to discuss the urgent need for economic equality (including reparations) that would begin to level the playing field and right centuries of injustice. He continues to insist on nonviolence as the essential tactic to achieve justice and equality.