In the early 1860's, in the town of Port Huron, Michigan, young Tom Edison is misunderstood by everyone except his mother Nancy and sister Tannie. When Tom accidentally sets off a smoke bomb in the school house cloakroom, his narrow-minded teacher, Miss Lavina Howard, calls him addled and expels him from school. Although Tom's father Samuel does not understand Tom and is disgusted with his behavior, Tom's mother retains her faith in her son. Soon after, Tom wins the gratitude of Mr. McCarney, the local telegraph operator, when he pulls his little son from the path of an oncoming train. The enterprising Tom gets a job selling concessions to passengers aboard the train, and when the Civil War starts, Tom begins to print a paper aboard the train informing passengers about the progress of the war. When Tom unwittingly carries a bottle of nitroglycerin aboard the train and sets fire to a car when one of his chemical bottles spills, he has his ears soundly boxed and is thrown off the train by Mr. Nelson, the railroad agent. Derided by the townfolk and his father, Tom plans to run away, but decides to stay when his mother falls gravely ill. In a desperate attempt to provide the needed light for an operation to save his mother's life, Tom breaks into the general store and steals a mirror to intensify the lamp light, only to be accused of theft for his ingenuity. Tom's invention helps the doctor save his mother's life, and he finally wins recognition for his heroism when he prevents a train wreck by sending a Morse code distress message on a train whistle. Tom's inventiveness wins him the admiration of the community and earns him a job as telegraph operator on the railroad. It also earns the respect of his father, who proudly tells his wife that from now on he will be known as the father of Tom Edison.