Coal Industry--19th century 5 Coal Industry--20th century 2 Coal mines and mining--Pennsylvania 2 Coal mines and mining--West Virginia--20th century 1 Estate administration--19th century 1 Family life--Pennsylvania--20th century 1 Family life--Personal correspondence--20th century 1 more ... Mines and Mining--Centre County (Pa.)--20th century 1 Mines and Mining--Clinton County (Pa.)--20th century 1 Quartermaters--19th century 1 less ...