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 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 1879 Western Union left the telephone business after losing a lawsuit against Alexander Graham Bell - the patent holder on the phone.