1914 was the year when Chicago's various streetcar companies were unified into the Chicago Surface Lines, while technically remaining separate companies. Chicago's entire streetcar system had become electrically powered in 1906, when the cable car system was phased out.

Red circles indicate streetcar barns.

At the time, route numbers had been adopted for internal use. But only the "Through Routes" were identified to the public by number.

Separate panels show transit routes on Chicago's north and south sides.