Subjects
- Petroleum industry and trade1
- Physician's Visiting Lists.1
- Physicians - letters and papers.1
- Poets and poetry.1
- Politicians -- United States1
- Politics and government.2
- Railroad Strike, U.S., 18771
- Railroad workers.1
- Railroads1
- Railroads - Baltimore and Ohio Railroad.1
- Reconstruction (U.S. history, 1865-1877)1
- Rivers and river valleys.2
- Schools1
- Steamboats1
- Surveyors and surveying.1