The Brookfield Zoo Map Shortly After Its Opening.
Decorative early map of the Brookfield Zoo.
In 1919, Edith Rockefeller McCormick donated land she had received from her father as a wedding gift to the Cook County Forest Preserve District for development as a zoological garden. The district added 98 acres to that plot and in 1921, the Chicago Zoological Society was established. Serious construction did not begin until 1926, after a zoo tax was approved. Construction slowed during the Great Depression, but regained momentum by late 1931. Construction went on at an increased pace and the zoo opened on July 1, 1934. By the end of September 1934, over one million people had visited the new zoo.