In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. America was on the verge of civil war and needed a reliable connection between the North and South. On the telegraph market of the USA at this time were operated with six large companies: American Telegraph Company, New York Albany and Buffalo Electro-Magnetic Telegraph Company, Atlantic and Ohio Telegraph, Illinois & Mississippi Telegraph Company, New Orleans & Ohio Telegraph Company, and the brainchild of Sibley & Co. - The Western Union Telegraph. July 3, 1884 the company's shares were included in the calculation base for the newly created stock index Dow Jones Transportation Average. Western Union made so that the time in all of American civil services was the same.