John E. O'Neill graduated from the United States Naval Academy in 1967 and after decorated service in Vietnam he finished as the top graduate of The University of Texas School of Law. Following a clerkship with Chief Justice William Rehnquist at the United States Supreme Court, O’Neill successfully tried several hundred cases and arbitrations, including representation for the People’s Republic of China in their first U.S. litigation. He declined any further representation of the PRC after the massacre at Tiananmen Square, where many innocent people died or disappeared.