In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. July 3, 1884 the company's shares were included in the calculation base for the newly created stock index Dow Jones Transportation Average. 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 1914 Western Union engineers invented the first payment card - a prototype of the modern credit card. Western Union made so that the time in all of American civil services was the same.