History 111 Sources 19 Indians of North America 13 Historic sites 11 Archives 10 Historical markers 9 Politics and government 9 more ... Antiquities 7 Historic Pennsylvania leaflets 7 Historic buildings 7 Description and travel 6 Social life and customs 6 Oral history 5 Societies, etc 5 African Americans 4 Anthracite coal industry 4 Art 4 Bibliography 4 Biography 4 Capital and capitol 4 Coal mines and mining 4 History, Local 4 Militia 4 Museums 4 Anniversaries, etc 3 Coal miners 3 Collective settlements 3 Conservation and restoration 3 Ethnic groups 3 Folklore 3 Fortification 3 Historic houses, etc 3 Methodology 3 Minorities 3 Petroleum industry and trade 3 Roads 3 Study and teaching 3 Working class 3 Administration 2 Anniversaries 2 less ...