Because Dr. King’s letter is a work of nonfiction, it does not necessarily contain characters; however, King does cite many historical and contemporary figures to build his argument. 

King’s Addressees 

In the letter, King addresses the eight Alabama clergymen who alluded to King and criticized his presence and actions in Birmingham in their open letter “A Call for Unity.” The clergymen are C. C. J. Carpenter, D.D., LL.D., Bishop of Alabama; Joseph A. Durick, D.D., Auxiliary Bishop, Diocese of Mobile, Birmingham; Rabbi Hilton L. Grafman, Temple Emanu-El, Birmingham, Alabama; Bishop Paul Hardin, Bishop of the Alabama-West Florida Conference of the Methodist Church; Bishop Nolan B. Harmon, Bishop of the North Alabama Conference of the Methodist Church; George M. Murray, D.D., LL.D., Bishop Coadjutor, Episcopal Diocese of Alabama; Edward V. Ramage, Moderator, Synod of the Alabama Presbyterian Church in the United States; and Earl Stallings, Pastor, First Baptist Church in Birmingham, Alabama. 

In their open letter, these eight clergymen condemned the actions of King and his fellow protesters, calling for negotiation in the courts as opposed to protests. They do not support civil disobedience and encourage the members of their congregations and the African American community as a whole to obey the decisions of the courts while they wait for change. 

Biblical Figures

In his introduction, King likens himself to the apostle Paul. Paul (who, like King, once wrote letters from a jail cell) left his hometown to promote the gospel; in the same way, King travels to cities like Birmingham to carry the “gospel of freedom.”

As King builds his argument for civil disobedience, he turns to Old Testament examples in the story of Shadrach, Meshach, and Abednego—three Jewish men condemned by King Nebuchadnezzar for their civil disobedience. When confronted with an unjust law, they chose to disobey in compliance to the “higher moral law” of God, and King argues that civil rights protesters are justified in doing likewise. King also admires the biblical figures of Amos, an Old Testament prophet; Jesus Christ; and the apostle Paul for being “extremists” for justice, love, and the promotion of the gospel. 

Ancient and Modern Writers and Theologians

In order to explain the difference between just and unjust laws, King turns to the writings of theologians and philosophers like St. Thomas Aquinas and Martin Buber. By their logic, King concludes that the segregationist laws are unjust and should be civilly disobeyed because they go against moral law and demote “persons to the status of things.” 

King refers to Socrates, seminal moral philosopher of Western thought, in his justification of civil disobedience. As he explains why he finds satisfaction in being labeled an “extremist,” King mentions John Bunyan, Martin Luther, Abraham Lincoln, and Thomas Jefferson, all of whom he considers to have been “extremists” for good. 

Near the end of his letter, King expresses his appreciation for White writers who have supported African Americans in their struggle for equal rights. He recognizes specifically Ralph McGill, anti-segregationist editor and publisher of the Atlanta Constitution; Lillian Smith, Southern social critic of the civil rights era and author of Strange Fruit; and Harry Golden, a journalist who spoke out against Jim Crow and segregation.

Contemporary Figures of the Civil Rights Era

Outlining the need for urgent nonviolent action, King mentions the Black nationalist leader Elijah Muhammad. King offers nonviolent protest as the alternative to the violent actions of Black nationalist groups like Muhammad’s and warns that without nonviolent protests as an option, the discontented African American community might resort to violent means. 

King demonstrates the necessity of urgent action in Birmingham through the example of Birmingham activist and minister Reverend Shuttlesworth, who (along with other civil rights leaders) organized a nonviolent protest advocating for the removal of racial signs in Birmingham. King hopes that the newly-elected mayor Albert Boutwell will be more open to negotiation with activists than was his opponent, Bull Conner, who is Birmingham’s public safety commissioner and strongly opposes the civil rights movement. 

At the end of his letter, King praises James Dabbs, a Southern liberal and civil rights supporter, as well as African American activists James Meredith and Mother Pollard (an elder in King’s church) for their determination and contributions to the civil rights movement.