From 1980 to 1983, Schillerstrom prosecuted cases as an Assistant State's Attorney for DuPage County. He later served as chairman of the DuPage County Board from December 1998 through December 2010.
Schillerstrom was employed as an Assistant State's Attorney in DuPage County between 1980 and 1983. Following this, he served as the chairman of the DuPage County Board from December 1998 to December 2010.