Inspiration from Overseas
In the early 1920s, when the Chicago Zoological Society was formed, barless exhibits were unheard of in U.S. zoos but were featured in several European zoos. These were based on the realistic designs of Carl Hagenbeck of the Tierpark, located near Hamburg, Germany.
 
In 1922, three officials and an engineer from the Forest Preserve District of Cook County set off to examine the Tierpark and to learn about barless designs from its directors, Lorenz and Heinrich Hagenbeck—Carl’s sons.
 
Eventually, the District officials returned to the United States, but the engineer stayed in Germany to work with the brothers on a preliminary plan for the Chicago Zoological Park.
 
Later, Chicago Zoological Society officers rejected the Hagenbeck plan for a centralized restaurant and an auto drive around the zoo’s perimeter. But when the zoo finally opened some 12 years later, its realistic exhibits, which relied on Hagenbeck-inspired moats instead of bars to separate animal from visitor, were an instant hit.