Design and construction Railroads 34 Costs 9 Bridges 4 Cars 4 African Americans 3 Electric railroads 3 more ... History 3 Locomotives 3 Railroad bridges 3 Surveying 3 Historical museums 2 Museums 2 Roads 2 Street-railroads 2 African American 1 Agriculture 1 Alleys 1 Baking 1 Beverage industry 1 Boat & ship industry 1 Bottle industry 1 Buildings 1 Buses 1 Canals 1 Cement industries 1 Chemins de fer 1 Commuting traffic 1 Conception et construction 1 Concrete construction 1 Construction industry 1 Dairying industry 1 Dedications 1 Design 1 Drawbridges 1 Dwellings 1 Electric power-plants 1 Employment 1 Engineers 1 Exhibitions 1 less ...