Carlton

Carlton Station [post office was] established in July, 1874, at the store of N. J. Reynolds. The point was formerly called Evans’ Bridge, and the name changed in April, 1876, when the station house was erected on the railroad, which crosses the north-east corner of the county, along the left bank of French Creek. 

History of Mercer County, 1877, page 41

After the building of the Franklin branch of the Erie Railroad early in the seventies, passing down the east side of the valley of French creek, a railroad station was established in the corner of Mercer county called Carlton. A postoffice was opened in July, 1874, with Nelson J. Reynolds as postmaster, and the office is now the only one in that corner of the county. 

Twentieth Century History of Mercer County, 1909, page 165 

Landowners in and near Carlton, from the 1873 Combined Atlas of Mercer County:  H. Smith, J. Nelson's heirs, Smith's Heirs, J. S. Smith, D. Nelson, H. Pattent, H. Smith, J. Cooley, School House No. 5 and Railroad Station.