Oldest Zoos in the United States: First Zoo in America, History & Top 10 List
Published: 21 May 2026
The oldest zoo in the United States is widely considered to be the Philadelphia Zoo, which opened in 1874 in Philadelphia, Pennsylvania. It is also often regarded as the first official zoo in America, although earlier animal menageries existed in cities like New York and Chicago before it was established.
The history of zoos in the United States is not straightforward. Before formal zoological parks were created, many cities kept small public animal collections in parks, which later evolved into modern zoos focused on education, conservation and scientific study.
In this guide, we’ll explore the oldest zoos in the United States, clarify which zoo truly came first and rank the top 10 oldest zoos still operating today.
When Was the First Zoo in America Created?
The first zoo in America is not tied to a single exact date because it developed gradually from early animal collections in the 19th century. The earliest public animal displays appeared in cities like New York and Chicago in the mid-1800s, where animals were kept in parks for public education and recreation.
The first formal step toward a true zoological institution came in 1859 with the establishment of the Philadelphia Zoological Society. This later led to the opening of the Philadelphia Zoo in 1874, which is widely regarded as the first official zoo in the United States.
These early menageries and structured zoological efforts eventually evolved into modern zoos focused on conservation, research, and education.
Early Menageries vs Modern Zoos in the United States
Early menageries in the United States were informal animal collections often displayed in parks or private exhibits, mainly for entertainment. These early displays lacked structured care systems or scientific goals.
Modern zoos, such as the Philadelphia Zoo and the Lincoln Park Zoo, are designed for education, research, and conservation, with a strong focus on animal welfare and habitat preservation.
Why the Philadelphia Zoo Is Considered the Oldest Zoo in the United States
The Philadelphia Zoo is considered the oldest zoo in the United States because it was the first institution in the country established with a formal zoological purpose focused on education, research, and animal care. Although it officially opened in 1874, its origins date back to 1859 with the founding of the Philadelphia Zoological Society.
Unlike earlier animal menageries in cities such as New York and Chicago, which were informal collections of animals displayed in public parks, the Philadelphia Zoo was designed as a structured zoological institution. This formal organization is what distinguishes it as the first true zoo in America.
Because of this combination of early founding plans, scientific purpose, and continuous operation, the Philadelphia Zoo is widely recognized as the oldest zoo in the United States.
History of Zoos in the United States
The history of zoos in the United States began in the early 19th century with informal animal exhibitions and public park menageries. These early collections were not formal zoos, but they introduced the idea of keeping animals for public viewing and education in urban spaces.
By the mid-1800s, cities such as New York and Chicago began developing more organized animal collections in public parks. These early efforts gradually evolved into structured zoological institutions with dedicated facilities, staff, and public missions.
The establishment of formal zoological institutions in the late 19th century, such as the Philadelphia Zoo and the Lincoln Park Zoo, represented a turning point in the evolution of modern zoos. These zoos introduced scientific management, education programs, and more systematic animal care.
In the 20th century, zoos across the United States shifted their focus from entertainment toward conservation, research, and wildlife protection. Modern zoos now play a major role in endangered species breeding programs, habitat preservation, and global conservation efforts.
READ: SAN DIEGO ZOO FACTS AND HIDDEN STORIES
Top 10 Oldest Zoos in the United States Still Open Today
This ranking is based on the earliest formally established zoological institutions and continuously operating public zoos in the United States, including their historical origins and current operation.
1. Philadelphia Zoo (1874)
- Founded: 1859 (zoological society formed)
- Location: Philadelphia, Pennsylvania
- Origin: First formal zoological society-backed zoo in the United States
- Significance: Established with a scientific and educational mission
- Status: Still operating today as one of the oldest zoos in the country
2. Lincoln Park Zoo (1868)
- Founded: 1868 (origins in public park animal collection)
- Location: Chicago, Illinois
- Origin: Began with donated animals in Lincoln Park
- Significance: One of the earliest continuously operating zoo sites in the US
- Status: Still operating today as a free public zoo
3. Cincinnati Zoo & Botanical Garden (1875)
- Founded: 1875
- Location: Cincinnati, Ohio
- Origin: Established as one of the first formal zoological gardens in the US
- Significance: Early leader in animal care and education
- Status: Still operating today as a major conservation zoo
4. Buffalo Zoo (1875)
- Founded: 1875
- Location: Buffalo, New York
- Origin: Started from early animal donations to a public park
- Significance: One of the earliest structured zoos in the United States
- Status: Still operating today as a city zoo
5. Roger Williams Park Zoo (1872 origins)
- Founded: 1872 (early animal collection)
- Location: Providence, Rhode Island
- Origin: Began as a small public park animal exhibit
- Significance: One of the earliest zoological park developments in the US
- Status: Still operating today as a modern zoo
6. Binghamton Zoo at Ross Park (1875)
- Founded: 1875
- Location: Binghamton, New York
- Origin: Established on donated public park land
- Significance: One of the oldest regional zoos in the United States
- Status: Still operating today
7. Maryland Zoo in Baltimore (1876)
- Founded: 1876
- Location: Baltimore, Maryland
- Origin: Began with animals displayed in Druid Hill Park
- Significance: One of the earliest Mid-Atlantic zoological parks
- Status: Still operating today as a major accredited zoo
8. Central Park Zoo (1860s origins)
- Founded: 1860s (animal collection origins)
- Location: New York City, New York
- Origin: Began as informal public animal menagerie
- Significance: One of the earliest public animal display sites in the US
- Status: Still operating today as a modern urban zoo
9. Cleveland Metroparks Zoo (1882)
- Founded: 1882
- Location: Cleveland, Ohio
- Origin: Began with donated animals and park land development
- Significance: One of the oldest continuously operating zoos in the Midwest
- Status: Still operating today as a major metropolitan zoo
10. Oregon Zoo (1888)
- Founded: 1888
- Location: Portland, Oregon
- Origin: Started as a small animal collection in the late 19th century
- Significance: Oldest zoo in the western United States
- Status: Still operating today as a conservation-focused zoo
So, What Is the Oldest Zoo in the United States?
The answer depends on how a zoo is defined in American history. The Philadelphia Zoo is widely considered the oldest formal zoo in the United States, established through the Philadelphia Zoological Society in 1859 and opened in 1874.
However, the Lincoln Park Zoo is often considered the oldest continuously operating zoo site in the country, dating back to 1868.
Because of these differences in definition, both zoos are recognized as “oldest” in different contexts of American zoo history.
READ: OLDEST ZOOS IN THE WORLD
Why Were Zoos Created?
Zoos were originally created to bring animals from different parts of the world closer to the public for education and observation. Early institutions helped people learn about wildlife that they would otherwise never encounter.
Over time, zoos evolved beyond public display and became centers for scientific research, conservation, and breeding programs for endangered species. Modern zoos also focus on protecting biodiversity and educating visitors about wildlife preservation.
Today, institutions like the Philadelphia Zoo and the Lincoln Park Zoo reflect this shift from entertainment-focused displays to conservation-driven missions.
READ: FACTS ABOUT ZOOS
Biggest vs Oldest Zoos in the United States
The oldest zoos in the United States are based on historical establishment dates, while the biggest zoos are defined by size, animal population, and species diversity.
For example, older zoos such as the Lincoln Park Zoo are important for their historical continuity, while larger modern zoos like the San Diego Zoo are known for extensive habitats and global conservation programs.
Because of this difference, a zoo can be historically significant without being large, and a large zoo may not be among the oldest in the country.
READ: BIGGEST ZOOS IN UNITED STATES
Most Famous Zoos in the United States
Some zoos in the United States are globally recognized not only for their size, but also for their conservation work, research programs, and visitor experience. These institutions attract millions of visitors every year and are often referenced alongside the oldest zoos in the country.
The San Diego Zoo is one of the most famous zoos in the world, known for its large open-air habitats and extensive wildlife conservation programs. It is widely regarded as a global leader in modern zoo design and animal care.
The Bronx Zoo is one of the largest metropolitan zoos in the United States, featuring thousands of animals across diverse natural-style habitats. It is especially known for its long history and large-scale conservation efforts.
The Smithsonian National Zoological Park is also among the most well-known zoos, particularly recognized for its research programs and its role in international wildlife conservation, including giant panda breeding efforts.
Together, these zoos represent the modern evolution of zoological parks in the United States, complementing the historical importance of the oldest zoos in the country.
READ: TOP 25 BEST ZOOS IN UNITED STATES
