Seven million fish in jars: inside the world's largest natural history collection
The Smithsonian's National Museum of Natural History in Washington holds over 148 million specimens, the largest natural history collection on Earth. Visitors see only a sliver. Behind the scenes sit 30 million insects, 4.5 million pressed plants and 7 million fish preserved in liquid-filled jars, with 3.5 million specimens out on loan every year.
The Smithsonian's national museum dates to 1846 and first lived in the building now called the Smithsonian Castle. As the collections swelled, it moved into a new National Museum Building, built in just 15 months and opened in 1881. Even that proved too small, and in 1902 Congress authorised a much grander home.
The neoclassical Natural History Building opened on March 17, 1910, though it was not finished until June 1911, at a cost of $3.5 million. It was the first structure raised on the north side of the National Mall under the 1901 McMillan plan, and for a time it also held the nation's history and art collections. The main building covers 1.5 million square feet, and its public galleries are free to enter and open 364 days a year, drawing 3.3 million visits in 2025.
It is also a working research centre, with about 185 professional scientists, said to be the largest such group devoted to natural and cultural history anywhere. Their work spans seven departments, from anthropology and botany to mineral sciences and paleobiology. The amphibian and reptile collection alone more than tripled between 1970 and 2020, from 190,000 specimen records to over 580,000, and field stations operate as far afield as Belize, Alaska and Kenya.
Big gifts built its best-known halls. A $20 million donation from Kenneth Behring in 1997 was among the largest in Smithsonian history, and a Hall of Mammals followed in 2003. In 2009 the museum marked 50 years of owning the Hope Diamond by giving the gem its own exhibit and a new setting, and in 2010 it opened a $21 million hall on human evolution. Its history carries unresolved questions too: an estimated 5000-plus sets of Native American remains are still held rather than returned to their communities.
Source: National Museum of Natural History
