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. 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. In October 1871 the company Western Union began to provide money transfer services, drawing on its own extensive telegraph network. 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.