The project was begun in 1874; the park was opened on November 11, 1875, and included a small section dedicated for animals.

In that year, Mayor Antonio Crespo created the "Buenos Aires Zoo", and separated it from the rest of the park.

Holmberg completed the assignment of the different parks, lakes and avenues, and began the exhibition of the 650 animals that the zoo had at that time.

Onelli added pony, elephant and camel rides to the zoo and increased the number of visitors (from 1,500 to 15,000) during his first year of office.

In December 2014, a Buenos Aires court ruled that a 29-year-old female Sumatran orangutan named Sandra living at the zoo was a "non-human person" who was entitled to some basic rights and could be liberated from her enclosure.

[12] The grassy areas of the park are full of native birds and rodents, which came to the zoo for the food thrown to the animals by visitors.

This part of the zoo was also home to turkeys, chickens, roosters, pigs, rabbits, cows, and horses.

[3] Big cats at the zoo included white tigers, pumas, cheetahs, jaguars, and lions.

Other animals at the zoo included red panda, camels, llamas, giraffes, bison, hippos, and elephants.