Former president Theodore Roosevelt presented six pairs of antelope horns to the Illinois State Museum in 1910 following a year-long hunting trip to East Africa. Roosevelt’s trip was billed as an expedition to collect specimens for the Smithsonian Institution in Washington, D.C. Roosevelt was a big-game hunter, but he was also a naturalist at heart, having created his own natural history museum in his room as a child. On this trip he mixed the two, traveling with support staff who would prepare the specimens and ship them home even as he continued hunting. In all, the Smithsonian received more than 11,400 specimens, including 1,000 large animal skins and 4,000 small mammals. The entourage also collected thousands of plants and cultural objects. Museums like the Illinois State Museum received the excess. The horns were on display when the ISM was housed in the Illinois State Arsenal building. They were one of the first exhibits encountered by visitors.

The Museum received two pairs of antelope horns each from the Eland, Hartebeast, and Oryx. The horns of male and female Elands differ in length and extent of spiraling. The Oryx is the smallest of the three but with horns measuring 38 inches long, which are nearly as long as the animal’s body. Because the horns are straight and parallel, they often appeared at a distance to be a single horn. This field identification mistake could be the basis of the mythical unicorn.