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. Most service points of Western Union work in the time convenient for customers throughout the week and throughout the year. 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. Western Union made so that the time in all of American civil services was the same.