Martin Luther King Jr. wrote the influential “Letter from a Birmingham Jail” in April 1963. This letter was addressed to eight white clergymen who criticized King's methods during the Civil Rights Movement. King eloquently defended the strategy of nonviolent resistance to racism and outlined the moral imperative for direct action. He argued against the notion of "waiting" for gradual change and emphasized the urgency of justice. The letter crystallized the principles of civil disobedience and the need to confront systemic injustice, making it a seminal document in both the Civil Rights Movement and American social justice discourse.