The precocious inventor is considered crazy by many; but his ideas produce some good results even in his youth.
Tom Edison (Mickey Rooney) pulls strings to wake his sister Tannie Edison (Virginia Weidler) but breaks a window, angering his father Sam Edison (George Bancroft). Tom uses Morse code to help Tannie in school. They are isolated, and Tom's experiment causes smoke. Sam punishes Tom with a strap. The school-teacher tells Sam and Nancy Edison (Fay Bainter) that Tom is expelled. Nancy encourages Tom and gives him apple pie. The family sings "Genevieve." Tom and Tannie send by telegraph that Indians are attacking. Tom saves a child from a train and is given copper wire by telegraph operator McCarney (J. M. Kerrigan). Tom is hoist up into a tree by Waddell and says he flew. Tom gives Joey Dingle (Bobby Jordan) gas. Nancy pretends to thrash Tom, and Mr. Dingle (Victor Kilian) hears Tom howling.
Nancy gives Tom a dime for candy, and he sells it on the train but can't get off. When he comes back, he has a business selling on the train. Tom rejects Joey and hires Tannie to help sell. Tom buys books on science. He loads a press on the train to print news during the Civil War. Tom gets information from Captain Brackett (Harry Shannon), who learns Tom has nitroglycerin. Conductor Nelson (Eugene Pallette) has the train stopped, and it is lowered into a river, where it explodes. Nelson tells Tom to get rid of his chemicals, but they start a fire. Tom and Nelson put it out, but Nelson dumps out Tom's equipment. Dr. Pender (Lloyd Corrigan) treats Tom's ear. Sam orders Tom he can't have chemicals in the house.
Tom tries to get a job, but people believe he is addlepated. Nancy has a pain, and Tom wants to move. He writes a note and leaves. Nancy needs a doctor, and Tannie finds the note. Tom asks McCarney for a loan. Tannie gets Dr. Pender and finds Tom. Tannie goes by train to get Bill Edison. Dr. Pender tells Tom he needs more light to operate on Nancy. Tom takes a mirror from Dingle's store and gathers lamps by it. Dr. Pender operates, and Tom returns the mirror. Dingle accuses him of stealing, and the mirror breaks. The railway bridge is out, and the lines are down. To stop the train Tom uses the whistle to send Morse code to Tannie. She hears the message and tells Nelson to stop the train, preventing an accident. Sam tells Tom he is proud of him. Sam pays Dingle for the mirror and then socks him. Tom gets a job as a telegraph operator for the railroad.
This true story shows how a bright youth may be considered
muddle-headed until he shows what he can do. Thanks to encouragement
from his mother and sister and his own ingenuity Tom Edison became
a great inventor.