In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. The size of the commission fee for the transfer is charged according to the Western Union tariffs and depends on the amount of money sent. July 3, 1884 the company's shares were included in the calculation base for the newly created stock index Dow Jones Transportation Average. In October 2006 the company made an initial public offering of shares on the New York Stock Exchange, becoming independent from First Data company. In October 1871 the company has implemented the world's first telegraph money order. After a century money transfers have become a major source of income for Western Union. In 1879 Western Union left the telephone business after losing a lawsuit against Alexander Graham Bell - the patent holder on the phone. Sibley, the founder of Western Union, did not build a new telegraph lines, and persuaded the other players to join. American Telegraph Company, however, still had to buy it.