About William E. Peterson:
William E. Peterson is a former Republican member of the Illinois Senate, representing the 26th district from 1993 to 2009. He had also served as the Assistant Minority Leader. Peterson previously served in the Illinois House of Representatives from 1983 to 1993. Peterson had announced that he would not seek reelection in 2008. Republican Candidate Dan Duffy of Lake Barrington defeated mayor of Round Lake Bill Gentes in the November 4, 2008 election.