Between 19, the Cincinnati Summer Opera performed in an open-air pavilion and were broadcast by NBC radio.
The zoo's original animal collection consisted of eight monkeys, two grizzly bears, three white-tailed deer, six raccoons, two elk, a buffalo, a laughing hyena, a tiger, an American alligator, a circus elephant, and over four hundred birds, including a crow. The first guide book about the Cincinnati Zoo was written in 1876 in German.
The 'Acclimatization Society of Cincinnati' was established in 1873 as similar organizations with imperial aims proliferated in Moscow, Berlin, London, and Melbourne in the late nineteenth century.
The land was purchased by Andrew Erkenbrecher and leased to the Zoological Society for 99 years.
It was founded on 65.4 acres (26.5 ha) in the middle of the city, and since then it has acquired some of the surrounding blocks and several reserves in Cincinnati's outer suburbs.
The zoo conducts breeding programs, and was the first to successfully breed California sea lions.
It introduced a wide savannah with some of Africa's most spectacular hoofstock, such as zebras, gazelles, lesser kudu, impala and giant eland, along with some of the world's largest birds like ostriches, marabou storks and grey crowned cranes.
Phase V, the final phase of the expansion, opened on July 23, 2016, The baby female hippo, named Fiona by zoo staff, is the first hippo to be born at the zoo in 75 years.
Fiona was also the first Nile Hippo to ever be captured on an ultrasound image.
After intensive care from zoo keepers, veterinarians, and NICU specialists at Cincinnati Children's Hospital, Fiona survived.
It was also home to the last living Carolina parakeet in 1918.
The zoo is an accredited member of the Association of Zoos and Aquariums (AZA), and a member of the World Association of Zoos and Aquariums (WAZA).