In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. In 1920, Western Union has implemented the world's first transmission of images over the ocean. 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 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.