Freeport is the county seat of Stephenson County, Illinois, United States. The population was 25,638 at the 2010 census, down from 26,443 at the 2000 census. The mayor of Freeport is George W. Gaulrapp, elected in 2005.
Originally called Winneshiek, the municipality when it was incorporated took its name from the generosity of Tutty Baker, who was credited with running a "Free Port" on the Pecatonica River. The name 'Winneshiek' was later adopted, and is preserved to this day, by the Freeport Community Theatre Group.
In 1837, Stephenson County was formed and in 1838, Freeport became its seat of government. Linked by a stagecoach with Chicago, the community grew rapidly. In 1840, a frame courthouse was erected and the first school was founded. Within two years, Freeport had two newspapers and in 1853, the two were joined by a third which published in German. By then, the community had a population of 2,000.