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 October 1871 the company has implemented the world's first telegraph money order. After a century money transfers have become a major source of income for Western Union. Thanks to cooperation with Western Union the Associated Press at the end of the XIX century took almost monopolistic position in the U.S. market news. In 1884 Western Union has become a joint-stock company and was brought to the stock exchange. The company has entered in the first American stock index Dow Jones.