According to this report from the AP, Western Union, the last operator providing telegram service has discontinued it's communications operations after 150 years of service. Samuel Morse discovered the technology and used it to send a simple message in the code that would later be given his name, "WHAT HATH GOD WROUGHT?" Even Morse understood that God was the creator of the laws around electromagnetism, and that he had merely harnessed it.
This is a technology that even into the 1970's found it's use in railroad communications. Speed and accuracy were the two qualities required for any agent manning a telegraph key. A mistake or delay in the transmission could be deadly. Train orders were tapped and clicked "down the line" to station agents to give to the engineer, sometimes "hooped up" to them on the fly. Interestingly, radio broadcasters today will talk to stations and use the same phrase to alert their agents "down the line."
In public use, telegrams were used to send all sorts of messages long distance. The senders would pay per word sent to advise of deaths, births, and emergencies. It was the cheapest way to send word quickly.
After more than ten years of the growing popularity of e-mail, the concept of paying per word has been lost in our information age. It is just as cheap to send a 5,000 word e-mail to everyone you know as it is to send a few words to a single person. It is easy--some would say too easy--to let everyone know the details of your life. Today's teens only know of Western Union as "the fastest way to send money." Some may not even know what a telegram was, let alone what it looked like or how they worked.
Our culture is changing. Even conventional radio is being phased out of certain portions of communications, like television and even car...radio. Sirius-ly. Eventually, satellite communications will replace much of what we thought radio had taken forever. One wonders what this bodes for the future of railroads.