South Park Commission (Chicago, Ill.). "Plan of the South Open Ground, the Upper Plaisance, the Midway Plaisance, the Lake Open Ground, the Lagoon Plaisance and the Parkway Quadrant." Map. Chicago: The Commission, 1871. Norman B. Leventhal Map & Education Center, https://collections.leventhalmap.org/search/commonwealth:4m90f747w (accessed April 19, 2024).