Morse signal receiver. An electrical telegraph was developed and patented in the United States in 1837 by Samuel Morse. His assistant, Alfred Vail, developed the Morse code signaling alphabet with Morse. At the Speedwell Ironworks in Morristown, New Jerse

Vail’s 1837 version improved significantly on Morses’s; here, Vail’s reception unit. (Science History Images/Alamy Stock Photos)