The Letter from Birmingham Jail (also known as "Letter from Birmingham City Jail" and "The Negro Is Your Brother") is an open letter written on April 16, 1963, by Martin Luther King, Jr. The letter defends the strategy of nonviolent resistance to racism. It says that people have a moral responsibility to break unjust laws, and to take direct action rather than waiting potentially forever for justice to come through the courts. Responding to being referred to as an "outsider", he wrote that “Injustice anywhere is a threat to justice everywhere“.
The letter was widely published and became an important text for the American Civil Rights Movement of the early 1960s.