In the 30's of the twentieth century, Western Union has become the world's largest telegraph company. 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 1849, Selden and Sibley, the founders of the future Western Union, created the New York State Printing Telegraph Company. Number of active holders of "Golden Card" of Western Union amounted to 9.5 million people worldwide.