Railroads 1,320 History 493 Street-railroads 160 Description and travel 156 Finance 156 Transportation 108 Canals 99 more ... Underground Railroad 96 African Americans 79 Railroads and state 60 Fugitive slaves 57 Employees 56 Railroad stations 52 Antislavery movements 48 Design and construction 45 Rates 45 Streets 45 Freight 44 Locomotives 41 Slavery 40 Coal 37 Early works to 1850 36 Electric railroads 35 Railroad law 35 Histoire 31 Management 31 Surveying 29 Abolitionists 28 Commerce 28 Employment 28 Railroad mortgages 26 Local transit 25 Railroad companies 24 Coal mines and mining 23 Pacific railroads 23 Bridges 22 Labor unions 22 Economic conditions 21 Railroad 21 Cars 20 less ...