Railroads 456 History 86 Finance 83 Street-railroads 72 Canals 49 Early works to 1850 31 Streets 21 more ... Transportation 18 Underground Railroad 17 Rates 15 Surveying 15 Coal mines and mining 14 African Americans 13 Description and travel 12 Electric railroads 12 Taxation 12 Freight 11 Fugitive slaves 11 Antislavery movements 10 Design and construction 10 Local transit 10 Street railroads 10 Coal trade 9 Management 9 Right of way 9 Appropriations and expenditures 8 Coal 8 Commerce 8 Location 8 Railroad law 8 Underground railroad 8 Bus lines 7 Railroad stations 7 Abolitionists 6 Costs 6 Race relations 6 Historic sites 5 Law and legislation 5 Railroads--Pennsylvania--19th century 5 Buildings, structures, etc 4 less ...