It was the telegraph invented by Samuel Morse in 1844 and there were establish many communication lines along the rail roads
railroad
Refrigerated railroad cars.
The railroad.
The invention of the steam engine and the railroad systems.
Railroad.(:
One invention that improved safety were automatic car couplers and railroad air brakes.
In 1874, he copatented (with Charles W. Brown) an improved toilet system for railroad cars called the Water Closet for Railroad Cars. A water closet for railroad cars is an on-board toilet. The phrase "water closet" means "room with a toilet" or modernly known "bathroom."
Telegraph lines were also built for transcontinental communication in the Pacific Railroad Act.
the railroad
railroad
improved transportation by railroads
Refrigerated railroad cars.
The railroad.
The invention of the steam engine and the railroad systems.
The invention of the standard gauge made a network of railroad lines possible.
The railroad train and the telegraph
The north could transport war supplies and soldiers