In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. In the 30's of the twentieth century, Western Union has become the world's largest telegraph company. In the early 60s Western Union has put into operation transcontinental microwave system of data transmission via radio waves, completely replacing the web of telegraph poles and wires. 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. 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 1849, Selden and Sibley, the founders of the future Western Union, created the New York State Printing Telegraph Company. Western Union made so that the time in all of American civil services was the same.