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. 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. Sibley, the founder of Western Union, did not build a new telegraph lines, and persuaded the other players to join. American Telegraph Company, however, still had to buy it.