The giant bird cage was a steel truss framework that spanned 228' by 84' by 50' tall that was designed by Frank Baker, Superintendent of the National Zoo.
The structure cost 17,5000 dollars.
The massive structure was divided into two sections; the first area held large birds and fowl, cranes, storks, pelicans, hawks, swans, pheasants, etc., and the other contained small birds of song and brilliant plumage.
Patrons could walk through a mesh wire 'tunnel' in the middle of the cage and view the over 1,000 birds on display and in flight.
Lee Gaskins' AT THE FAIR The 1904 St. Louis World's Fair
A public outcry saved relocation of the aviary to the National Zoo in Washington, D.C., and in 1905 the city of St. Louis purchased it for 3,500 dollars (that did not include any birds), which led to the establishment of the St. Louis Zoo, the first municipally supported zoo in the world.
The Bird (or Flight) Cage housed the Smithsonian's U. S. bird exhibit.
The city also paid 7.50 dollars for a pair of Mandarin ducks and 20 dollars for four Canada geese. A few local residents donated owls to add to the new collection.
In 1967, the interior of the flight cage was remodeled to include a boardwalk; in 1996, the St. Louis Zoo restored the super-structure of the birdcage.
The Bird Cage Restaurant cost 10,000 dollars to build.