The library's original building is an architectural gem in the downtown area. This two-story Roman brick structure with limestone trim was built in 1910 with partial funding from Andrew Carnegie. It is one of the contributing structures to the Monument Square Historic District, which is listed in the National Register of Historic Places. A 10,000-square-foot warehouse-like addition was opened in 1966, with the expectation that the facility would meet the needs of the community for the ensuing 20 years.
The project expanded the library to 43,334 square feet with 55 adjacent parking spaces. This was accomplished by removing the existing addition, renovating the 1910 building, and constructing a new, 34,434-square-foot addition, creating entrances on both West Street and Pearl Street.