The Old Indiana County Courthouse (601 Philadelphia St.) was listed on the National Register of Historic Places in 1974. Text below was adapted from a copy of the original nomination document. 
The Indiana County Courthouse is a three and one-half story structure, nine bays wide and five deep. It has a high mansard roof surmounted by a center clock tower. The Indiana County Courthouse was designed in 1869-70 by James W. Drum, architect, in what he called "Modern Renaissance style," or Second Empire style. It was to replace an earlier courthouse used from 1808 to 1868, which had become inadequate to meet the county' needs. The building maintains a stately appearance through simplicity of form, the classical entrance, and mansard roof.
The building is constructed of brick, with cut stone corner quoins and stone facing on either side of the entrance. The main classical-style entrance is five bays in width with two story high windows surmounted by hooded molding. Above the belt course which runs the length of the first floor, rest four stone Corinthian columns which support cast iron capitals and an entablature crowned by a triangular pediment. The well-proportioned pediment is trimmed with modillions, as is the entire cornice. Dormer windows, topped by segmental pediment protrude from the roof at various places. Second and third story windows (with the exception of the main entranceway) are topped by simple pediments. An impressive clock tower dominates the structure: a large clock projects from each of the four faces of a conical roof. The lower section of the tower is a square tambour around which are twenty Corinthian columns and an entablature. Louvered windows appear between the columns. The top of the dome is finished with cast iron cresting.
The interior of the courthouse is in good condition, and is decorated richly in classical motifs. Fine marble detailing, woodwork, and frescoes make this building one of the more luxuriant in the county.
The appearance of the building is very close to original. Alterations have included the removal of the original cast iron cresting in 1917. In 1929 the basement floor was excavated. Some interior fixtures have been replaced, most notably the stained glass work in the courtroom. The entire exterior was sandblasted and repointed during the 1950's. The Old Indiana County Courthouse is presently occupied by the National Bank of the Commonwealth which has entered into a 50 year restoration job of restoring and freshening the original appearance of the building, while maintaining its architectural integrity. The brick work was repointed and treated with weatherproof sealant. The woodwork was replaced where necessary and refinished in its entirety. The dome was refinished, new clock face and hands installed, and the clock itself set into motion.
As the Indiana County Courthouse for 100 years (1870-1971) this building exemplifies the role of the county courthouse in the life of rural Pennsylvania. The Old Indiana County Courthouse was the repository for important documents as well as the headquarters for most government agencies. Citizens entered the building for purposes ranging from purchase of a dog license to serving jury duty. In a relatively sparsely populated area, and because the courthouse served many necessary everyday functions, most citizens were likely to know personally some occupants of the courthouse. Thus the rural people of the county "related to their courthouse in a personal way and on a frequent basis."
The Old Indiana County Courthouse was also the site of special events in the history of Indiana County. It was the scene of the only speech ever given in the county by a Presidential candidate when John F. Kennedy spoke there in 1960.
The original tract of land for the Indiana County seat, where the courthouse now stands, was donated by George Clymer prominent colonial figure and signer of the Declaration of Independence. Much later John S. Fisher practiced in the courthouse as a member of the Indiana county bar. He later became a State Senator, served as the Commonwealth's first Secretary of Banking, and ultimately was elected Governor of Pennsylvania.
Architecturally the Old Indiana County Courthouse is an excellent example of the Second Empire style. Its high mansard roof with curb, dormer windows, and classically detailed chimneys are all characteristic features of that style. The "grand boldly modeled emphatically three-dimensional" appearance of these buildings became the focal point in many small communities like Indiana. The simplicity of form in this courthouse is reinforced by the combination of materials. The use of brick and stone recall the Georgian tradition and contributes to the building's stately appearance, while the cast iron capitals on the stone columns exempligy the beginning of the use of industrial architectural components. The Indiana County Courthouse is a fine illustration of the popularity of the Second Empire style for public buildings, whose character and requirements were well-suited to the use of that style.
Barber, Richard, The Indiana County Courthouse, Indiana, Pennsylvania. (Unpublished manuscript, 1966).
Caldwell, J.A., History of Indiana County, Pennsylvania (J.A. Caldwell, 1880, pp.321-323).
Stephenson, Clarence D., "Indiana County's First and Second Courthouse," Indiana County, Pennsylvania (The Commissioners of Indiana County, 1971, pp.10-11).
Stephenson, Clarence D., The Founding of Indiana, Pennsylvania (Mahonning Mimeograph and Pamphlet Service).
Stewart, Professor J.T., Indiana County, Pennsylvania (J.H. Beers & Co. 1913).