In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. 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. In April 1851 companions registered in Albany New York and Mississippi Valley Printing Telegraph Company (NYMVPTC), which included founded two years before New York State Printing Telegraph Company. 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 1856, in 7 years after the foundation of New York State Printing Telegraph Company, the company changed its name to Western Union Telegraph Company. Western Union made so that the time in all of American civil services was the same.