It’s hard to overstate how much the development of the telegraph changed not only the United States but the world. A relatively simple electrical circuit allows the telegraph key to send a series of pulses to another station, causing a clicking device called a sounder to move. This Western Electric 19th century telegraph key and sounder is a good example of the devices that would, in a few short decades, go from being a curiosity to the backbone of communications in the US. In fact, in the first five years of public telegraph use, the length of telegraph wires in the country would expand by more than 12,000 miles and be run by 20 different companies.