Railroads allowed for the transport of material between nations and also allowed the transportation industry to grow so people could get from places like New York to San Francisco in a matter of days instead of the weeks is would have taken before.
Canals allowed for nations to move supplies much faster like for example the Suez canal allowed people going from Europe and the Mediterranean to go to Asia much faster because they didn't need to go around Africa
Roads in the modern sense allowed for people to drive between cities much faster and allowed for the transportation of good much easier for example you could go from Atlanta to DC in the about a day wall it would have taken much longer before hand
Important people
Richard Trevithick built the first train in 1804
Teddy Roosevelt helped open the Panama Canal
And Dwight Eisenhower was the president who approved the building of the highways that connect all the continental US