Railroads 74 Street-railroads 66 Streets 36 History 34 Local transit 22 Railroad stations 20 Railroads, Elevated 19 more ... African Americans 12 Street railroads 11 Transportation 11 Electric railroads 10 Subways 8 Underground Railroad 8 Bridges 7 Bus lines 7 Crossings 7 Employment 7 Finance 7 Women 7 Buildings, structures, etc 6 Cars 6 Civil rights 6 Railroad bridges 6 Railroad employees 6 Design and construction 5 Law and legislation 5 Transit systems 5 Trolley cars 5 Appropriations and expenditures 4 Commuters 4 Employees 4 Race relations 4 Railroad locomotives 4 Roads 4 Segregation in transportation 4 Stations 4 Abolitionists 3 Architecture 3 Buildings 3 Buildings and structures 3 less ...