In 1855, the first railroad through Lake County was completed, running from Chicago through the county line. Henry Ostrander owned the land where the depot was to be placed, and he agreed to donate the site if the depot were called "Rockland." Therefore, this area, known previously as the Dwyer Settlement and Oak Hill, became Rockland, the only stop between Highland Park and Waukegan. Rockland had a post office and general store on Mawman Avenue with a small school and church located west of the tracks near Green Bay Road.