Although it still exists, the telegraph has been all but forgotten in a world dominated by instant digital messaging, relegated to the archives of 20th-century institutions alongside the corner phone booth and the horse and buggy. Yet there was a time when this form of communication was the best and most efficient way to deliver a message across significant distances. Western Union, the largest provider of the service, logged more than 200 million telegrams sent in its peak year of 1929. Give...