Martin Luther King, Jr.

 A police officer on a motorcycle rolls his machine in front of civil rights leaders Rev. Ralph Abernathy, left, and Rev. Martin Luther King Jr., center, as they lead a march protesting against segregation, in Birmingham, AL, on April 12, 1963.
Horace Cort/AP Photo
Rev. Ralph Abernathy, left, and Rev. Martin Luther King Jr., right are taken by a policeman as they led a line of demonstrators into the business section of Birmingham, AL, on April 12, 1963. King and Abernathy would go on to spend eight days in Birmingham jail where King would go on to write his seminal letter.
Horace Cort/AP Photo

from Letter from a Birmingham Jail, 16 April 1963, by Martin Luther King, Jr.:

You deplore the demonstrations that are presently taking place in Birmingham. But I am sorry that your statement did not express a similar concern for the conditions that brought the demonstrations into being. I am sure that each of you would want to go beyond the superficial social analyst who looks merely at effects and does not grapple with underlying causes. I would not hesitate to say that it is unfortunate that so-called demonstrations are taking place in Birmingham at this time, but I would say in more emphatic terms that it is even more unfortunate that the white power structure of this city left the Negro community with no other alternative.