What new uses for steel were developed at
this time?

although the railroads were the biggest consumers of steel there were other uses including barbed wire, and farm machines. it also made new construction methods possible including steel cables for the brooklyn bridge and steel frames for the first skyscrapers.

map scale refers to the relationship (or ratio) between distance on a map and the corresponding distance on the ground. for example, on a 1: 100000 scale map, 1cm on the map equals 1km on the ground.