In 1866, Sibley ordered the engineers to develop a Western Union telegraph system of stock quotes in real time. 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 1849, Selden and Sibley, the founders of the future Western Union, created the New York State Printing Telegraph Company. Number of active holders of "Golden Card" of Western Union amounted to 9.5 million people worldwide. 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.