Shortly after graduating from Yale Law School in 1963, Cahn started his career in government as special counsel and speechwriter for Attorney General Robert Kennedy under President John Kennedy. He wrote Robert Kennedy's 1964 University of Chicago Law Day address. In 1964, he served as the Executive Assistant to Robert Sargent Shriver, Jr., focusing his efforts on issues related to poverty and hunger under the newly created Office of Economic Opportunity. That same year, Cahn and his wife Jean Camper Cahn co-authored an article in the Yale Law Journal, "The War on Poverty: a Civilian Perspective". This formed the basis for the establishment of the Legal Services Corporation.
Cahn left government work in 1968 to focus his efforts more exclusively on defending the rights of Native Americans. Cahn established the Citizens Advocate Center as a watchdog organization to "monitor governmental programs and assure equitable treatment of all community organizations in their dealing with the government." The Citizens Advocate Center published Our Brother's Keeper, the Indian in White America in collaboration with leading Native American rights activists in 1969. Such efforts helped catalyze the adoption of policies increasing the level of self-determination of Native American populations. By the 1970s, the organization had adopted a broader mission of "function as a watchdog of federal grant-making agencies having significant impact on low-income citizens...and the effectiveness and responsiveness of the administrative process, including the administration of federal housing programs."
In keeping with their belief that the legal system should be used as an instrument for promoting social justice, Edgar and Jean Camper Cahn co-founded the Antioch School of Law, a subunit within a network of institutions run by Antioch University. As law-school deans, Edgar and Jean pioneered clinical legal education in the United States, incorporating clinical experience into a curriculum that included the traditional case study methodfor the first time. When financial distress at Antioch University forced it to close several of its subunits in the late 1980s, the Council of the District of Columbia bought the school, renaming it the District of Columbia Law School, preserving the law school's faculty and curriculum The new law school was awarded provisional American Bar Association accreditation in 1991 and incorporated into the University of the District of Columbia in 1996. Two years later, the institution was renamed in honor of David A. Clarke, a former city council chairman who had been particularly supportive of the school and its mission. The David A. Clarke School of Law at the University of the District of Columbia was awarded full ABA accreditation in 2005.
Making Equal Justice Under Law a Reality: The Role of the Lawyer as Volunteer. Harriet Lowenstein Goldstein series: The volunteer in America 4; Florence Heller Graduate School for Advanced Studies in Social Welfare Papers in social welfare. Waltham, Massachusetts: Brandeis University, Florence Heller Graduate School for Advanced Studies in Social Welfare, 1968.
Our Brother's Keeper: The Indian in White America. Washington, New Community Press, 1969.
Citizen participation : a case book in democracy. Trenton, New Jersey: New Jersey Community Action Training Institute, 1969.
The legal lawbreakers : a study of the nonadministration of Federal relocation requirements. Washington : Citizens Advocate Center, 1970
Citizen Participation: Effecting Community Change. Praeger special studies in U.S. economic and social development. New York: Praeger, 1971.
Time Dollars: The New Currency that Enables Americans to Turn Their Hidden Resource - Time - into Personal Security & Community Renewal. Emmaus, Pennsylvania: Rodale, 1992.
No More Throwaway People: The Coproduction Imperative. Washington, DC: Essential Books, 2000.
