Steel and gasoline made a contribution to raw material and fuel. Steel was used to build almost 200,000 miles of railroads in just 40 years, build larger ships and more affordable automobiles. Inventions in the railroad industry included air brakes, Pullman cars, and the standard gauge improved railway transportation. Air brakes provided safety, Pullman cars provided passenger travel rather than just freight travel, and the standard gauge allowed trains to travel on any track.
sorry, went back into an essay i wrote awhile back for the answer
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