Nixon Theater, [103]
Oakland annexed to Pittsburgh, [52]
O'Hara, James, [84]
Ohio & Pennsylvania Railroad, [49]
Ohio Company formed, [16]
Osgood, Lucius, [118]
Parke, J. E., [118]
Paur, Emil, [94]
Pearson, A. L., [63]
Peebles annexed to Pittsburgh, [52]