In the 30's of the twentieth century, Western Union has become the world's largest telegraph company. Leaving the idea of expansion into Europe, Western Union took up the expansion of services in the U.S. market. July 3, 1884 the company's shares were included in the calculation base for the newly created stock index Dow Jones Transportation Average. In 1933, by the Western Union Company were invented "singing telegrams". In 1849, Selden and Sibley, the founders of the future Western Union, created the New York State Printing Telegraph Company.