Who made the first telegraph prototype and in what year?
While Americans generally attribute the invention of the telegraph to Samual Morse, who developed an electronic telegraph in 1837 and received a patent for his design in 1847, he actually was not the original inventor of telegraph as a means of wired communications. Some histories of the telegraph attribute the invention of the first electric telegraph to Samuel Soemmering in 1809. Going back even earlier, a non-electric telegraph had been developed by Claude Chappe in 1794.
In short, what was thought to be an easy answer to a basic question is anything but. If the question is limited to the United States, then Samuel B. Morse is the answer. If the scope of the question is broadened, then Chappe and Soemmering belong in the discussion.