The Letter from Birmingham Jail was an open letter written on April 16,
1963 by Martin Luther King, Jr., an American civil rights leader. King
wrote the letter from the city jail in Birmingham, Alabama, after a 
peaceful protest against segregation. The letter is a response to a 
statement made by eight white Alabama clergymen on April 12, 1963 
titled "A Call For Unity" which agreed that social injustices were taking
place but expressed the belief that the battle against racial segregation
should be fought solely in the courts and not taken onto the streets.
King responded that, without forceful, direct actions such as his, true
civil rights could never be achieved. As he put it,
 
"This 'Wait' has almost always meant 'Never.'
 
He asserted not only that civil disobedience is justified in the

face of unjust laws, but also that "one has a moral responsibility 

to disobey unjust laws." The letter was first published as "Letter 

from Birmingham Jail" in the June12, 1963 edition of The Christian

Century The letter includes the frequently quoted lines that 
 
"Injustice anywhere is a threat to justice everywhere,"

as well as the words of  Thurgood Marshall
 
"justice too long delayed is justice denied."