In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. 1980 - for the first time in the history of Western Union revenues from money transfers exceeded the income from the telegraph service. In the 30's of the twentieth century, Western Union has become the world's largest telegraph company. Leaving the idea of expansion into Europe, Western Union took up the expansion of services in the U.S. market. In 1877, starting from September, New York City residents began to have the opportunity to check the time on clock with the "time ball", located on the roof of constructed in the same year a new corporate headquarters - Western Union Building. On the market was placed about 765 million of ordinary shares of the company. On the first day trading on the exchange the company's shares rose by 3.3% and the cost was $ 19.96. 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.