Railroads 425 History 98 Street-railroads 83 Finance 59 Canals 49 Early works to 1850 27 Underground Railroad 25 more ... Transportation 19 Streets 17 Rates 15 Surveying 15 African Americans 12 Electric railroads 12 Fugitive slaves 12 Taxation 12 Antislavery movements 11 Coal mines and mining 11 Freight 11 Coal trade 9 Commerce 9 Design and construction 9 Management 9 Right of way 9 Appropriations and expenditures 8 Description and travel 8 Location 8 Railroad law 8 Abolitionists 7 Coal 7 Local transit 7 Railroad stations 7 Bus lines 6 Cars 6 Costs 6 Histoire 6 Law and legislation 6 Race relations 6 Street railroads 6 Buildings, structures, etc 5 Historic sites 5 less ...