 Using scraps of paper given to him by a janitor , notes written on the margins of a newspaper , and later a legal pad given to him by SCLC attorneys , King wrote his essay " Letter from Birmingham Jail " . It responded to eight politically moderate white clergymen who accused King of agitating local residents and not giving the incoming mayor a chance to make any changes . Bass suggested that " Letter from Birmingham Jail " was pre @-@ planned , as was every move King and his associates made in Birmingham . The essay was a culmination of many of King 's ideas , which he had touched on in earlier writings . King 's arrest attracted national attention , including that of corporate officers of retail chains with stores in downtown Birmingham . After King 's arrest , the chains ' profits began to erode . National business owners pressed the Kennedy administration to intervene . King was released on April 20 , 1963 . 
