Hillman has experience adjudicating antidumping, countervailing duty, patent and safeguards cases as a result of her nine-year service as a Commissioner at the United States International Trade Commission, from 1998 to 2007. She was vice-chair 2002–2004. Through her work as the General Counsel at the Office of the United States Trade Representative, 1995–1997, Hillman was involved in all litigation matters in which the United States was a party or third party in disputes before panels of the NAFTA or the WTO. She negotiated mutually acceptable agreements with over 45 countries while serving as USTR's Ambassador and Chief Textiles Negotiator from 1993 to 1995. She had worked on the Clinton transition in 1992–1993.
