In the early forties of the 20th century, Western Union has used the first time a commercial intercity microwave transmission system. In 1920, Western Union has implemented the world's first transmission of images over the ocean. In the 30's of the twentieth century, Western Union has become the world's largest telegraph company. In 1860 the U.S. Congress arranged among the telegraph companies a competition to create a national line. The winner was Western Union. In 1864, fearing the laying of long underwater lines, Western Union offered to carry out laying of telegraph lines to Europe through the Russian Alaska under the narrow Bering Strait and then to Siberia with branching in the major cities of Europe. 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.