Four settlers claimed four tracts of land that would become the city of Osage: Hiram Hart, 80 acres (32 ha) that is the southwest side; Dr. A.H. Moore, 80 acres (32 ha) for the southeast side; O.E.

[2] The city was named for Orrin Sage, a banker from Massachusetts who contributed to the Gibbs, Boardman Company of Lyons, Iowa, which represented the speculative land interests of investors such as Sage.

Its development to the west was the result of the location of the Illinois Central Railroad tracks and the Mitchell County Courthouse in the late 1860s.

The district contains a mix of retail commercial buildings, movie theaters, fraternal halls, professional offices, a cafe, a library, and auto-related businesses.

The buildings range in size from one to three-story commercial blocks, and a majority of them are masonry construction.