Three dioramas were produced by National Park Service museum technicians in 1940 as part of the first exhibits installed in the Old Courthouse. These dioramas, along with three more fabricated in the 1950s, were part of the exhibits on display at the Old Courthouse until the late 1970s.

In 1976, the Museum of Westward Expansion opened under the Arch, but the dioramas and other exhibits were not used in the new museum. All six of the dioramas, however, were kept on display at the Old Courthouse to depict significant events in westward expansion and as examples of early National Park Service exhibit craftsmanship.