Railroads 1,320 History 383 Street-railroads 160 Finance 152 Underground Railroad 96 Canals 87 Transportation 84 more ... Description and travel 69 Railroads and state 60 African Americans 58 Employees 56 Railroad stations 52 Fugitive slaves 51 Freight 44 Rates 43 Antislavery movements 42 Design and construction 42 Streets 39 Early works to 1850 36 Electric railroads 35 Railroad law 35 Locomotives 30 Management 29 Surveying 28 Railroad mortgages 26 Commerce 24 Local transit 24 Railroad companies 24 Coal 23 Pacific railroads 23 Slavery 23 Abolitionists 22 Employment 22 Railroad 21 Cars 20 Railroad bridges 20 Railroads, Elevated 20 Taxation 20 Bridges 19 Labor unions 19 less ...