 After law school and after two years in the United States Army, he clerked for Emile Zola Berman, an internationally known trial lawyer who represented Sirhan Sirhan, and Ephraim London, a Supreme Court advocate and Constitutional lawyer whose firm represented Alger Hiss, and who won every one of the nine cases he argued before the Supreme Court.He was in 1966 co-director of the Columbia University Center on Social Policy and Law while he taught law at Columbia.He was director counsel of the Roger Baldwin Foundation of the ACLU, legal director and associate director of the ACLU, as well as director of the Lawyers Committee to Defend Civil Rights, ran for political office in 1974 and formed his own law firm, Frankfurt Garbus in 1977.