In 1906, Congress appropriated funds for a new post office building in Marion, Ohio.  James Knox Taylor, Supervising Architect of the Treasury, designed a neo-classical structure, reflecting the architectural tastes of the era.  The building was opened to the public December 26, 1910.  An addition at the rear of the building was completed in March, 1924.  It was removed and replaced with a larger addition in 1936-1937.

     When the federal government offered the building for sale in the 1980s The Marion County Historical Society (MCHS) accepted the challenge and purchased the “Old Post Office."  The façade and lobby of the Old Post Office (renamed Heritage Hall by MCHS) were listed on the National Register of Historic Places in 1990.  Much work was done to make the building suitable for use as the Society’s headquarters and museum.

     The largest room on the main floor is the former mail sorting room. This sky-lighted space is now the main gallery of The Marion County Historical Society Museum.  At ceiling level along the east and south walls are tunnels with viewing slits.  These areas were only accessible via a locked spiral staircase for which the postal inspector held the only key.  From the viewing areas the postal inspector observed employees at work.  The lower level of Heritage Hall contains galleries devoted to the life and career of Warren G. Harding, a Marionite and 29th President of the United States.

     For more than 75 years, Marionites visited their Old Post Office on a regular basis.  Now that the building has a new life as Heritage Hall, it hosts local residents and tourists year around.  Within its walls, they learn of the building’s previous use.  Exhibitions on two levels provide insight into the history of Marion County.  In this way, Heritage Hall and The Marion County Historical Society continue the original public service function of the Old Post Office.