Levison was instrumental in all the activities of the Southern Christian Leadership Conference (SCLC), the organization established by Dr. King and other Southern black preachers to further the cause of civil rights. He professionalized the fund raising of the organization and took on many of the publicity tasks, in addition to serving as Dr. King's literary agent. He was also a close adviser to Dr. King and a ghostwriter for him. Levison co-wrote with Clarence Benjamin Jones one of the drafts for Dr. King's "I Have a Dream" speech presented at the March on Washington for Jobs and Freedom on August 28, 1963. Some of Levison's conversations with Dr. King are reproduced verbatim from FBI wiretaps in Taylor Branch's biography of Dr. King, "Parting the waters : America in the King years, 1954-63". Levison himself initiated the end of his public association with Dr. King in 1963, following the revelation to Dr. King's circle that Attorney General Robert F. Kennedy and then President John F. Kennedy had pressured Dr. King in person to break with Levison (and Jack O'Dell). But Levison continued to advise Dr. King privately until Dr. King's assassination in April 1968, and afterwards Levison continued to work with Dr. King's wife Coretta Scott King. The Poor People's Campaign in Washington, DC that took place from May 12, 1968 – June 24, 1968 was based on Levison's proposal.