The museum was conceived as part of President Capen's campaign to expand the university.
Barnum, who was a lifelong Universalist supporter for which Tufts was affiliated, was targeted for the campaign.
In May 1883, Capen persuaded Barnum to give the money under the agreement that the transaction be kept under secrecy and that once his identity be disclosed the building would 'forever be called the Barnum Museum of Natural History.'
The building was built to accompany his museum in Bridgeport, Connecticut.
The building was designed by architect J. Phillip Rinn from the firm Andrews, Jones, Biscoe & Whitmore.
The original building stood two stories above a basement with a laboratory and lecture room.
The ground floor included a library and a vestibule.
The upper floors contained a grand hall, 34 feet high, intended for the display of the specimens.
Rinn designed the building in cohesion with the Goddard Chapel to give the campus a sense of homogeneity.

The museum incorporated specimens which Tufts professor John Marshall had amassed during the previous decades, mostly rocks and minerals.
Additionally, Mary Goddard, one of Tufts' earliest benefactors provided the museum with an array of coins, ethnological material, and stuffed birds.
For Barnum, the museum was one of the first of many natural history collections which he provided to over 200 American universities.

After Barnum's death in 1891, the museum continued to prosper.
A further $40,000 provided by Barnum gave the museum two new wings and several new collections.
The university constructed the west wing in 1894 and added a new biological laboratory, classrooms, and library.
An east wing was built in 1935 for labs and offices.
The third addition, the Dana Laboratory, was built in 1963.
At a cost of $750,000 it was built using funds from the National Science Foundation.
The addition was designed by Perry Shaw, Hepburn and Dean and was named for Charles Dana.
The museum was conceived as part of President Capen's campaign to expand the university. Barnum, who was a lifelong Universalist supporter for which Tufts was affiliated, was targeted for the campaign. In May 1883, Capen persuaded Barnum to give the money under the agreement that the transaction be kept under secrecy and that once his identity be disclosed the building would 'forever be called the Barnum Museum of Natural History.' The building was built to accompany his museum in Bridgeport, Connecticut. The building was designed by architect J. Phillip Rinn from the firm Andrews, Jones, Biscoe & Whitmore. The original building stood two stories above a basement with a laboratory and lecture room. The ground floor included a library and a vestibule. The upper floors contained a grand hall, 34 feet high, intended for the display of the specimens. Rinn designed the building in cohesion with the Goddard Chapel to give the campus a sense of homogeneity.
The museum incorporated specimens which Tufts professor John Marshall had amassed during the previous decades, mostly rocks and minerals. Additionally, Mary Goddard, one of Tufts' earliest benefactors provided the museum with an array of coins, ethnological material, and stuffed birds. For Barnum, the museum was one of the first of many natural history collections which he provided to over 200 American universities.
After Barnum's death in 1891, the museum continued to prosper. A further $40,000 provided by Barnum gave the museum two new wings and several new collections. The university constructed the west wing in 1894 and added a new biological laboratory, classrooms, and library. An east wing was built in 1935 for labs and offices. The third addition, the Dana Laboratory, was built in 1963. At a cost of $750,000 it was built using funds from the National Science Foundation. The addition was designed by Perry Shaw, Hepburn and Dean and was named for Charles Dana.
Barnum Museum of Natural History