In the 30's of the twentieth century, Western Union has become the world's largest telegraph company. In 1866, Sibley ordered the engineers to develop a Western Union telegraph system of stock quotes in real time. July 3, 1884 the company's shares were included in the calculation base for the newly created stock index Dow Jones Transportation Average. 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.