Leaving the idea of expansion into Europe, Western Union took up the expansion of services in the U.S. market. Another invention of Western Union - time synchronization. Each money transfer is protected with control number, that allows you to track and to ensure prompt payment of money specified by you person. In 1866, Sibley ordered the engineers to develop a Western Union telegraph system of stock quotes in real time. In 1877, starting from September, New York City residents began to have the opportunity to check the time on clock with the "time ball", located on the roof of constructed in the same year a new corporate headquarters - Western Union Building. One of the common kinds of money transfer is a transfer via the international system of Western Union. 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.