In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. In 1866, Sibley ordered the engineers to develop a Western Union telegraph system of stock quotes in real time. 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.