He received his certificate from the New York Bar Association in 1963, while serving as a clerk for Supreme Court Justice William J. Brennan, Jr.
Posner went on to continue his law career in the U.S. Justice Department as assistant to the Solicitor General Thurgood Marshall. After serving on President Lyndon B. Johnson's Task Force on Communications Policy and teaching law at Stanford University, Posner ended up at the University of Chicago Law School where he has been a senior lecturer since 1981.
Posner was appointed to the U.S. Court of Appeals for the Seventh Circuit in Chicago in 1981. He served in the position till 1993 when he was named Chief Judge, his current position.
Judge Posner is considered one of the founders of the "Chicago school" of law and economics, which applies the principles of ecomonics to analyze the legal system. He has written over 20 books on a variety of legal subjects including "Antitrust Law: An Economic Perspective" in 1976 which one Amazon.com reviewer wrote, "describes in easy-to-understand terms why monopolies are bad from an economic point of view."
Posner married Charlene Ruth Horn on August 13, 1962. The couple has two children, Eric and Kenneth.
