Edison eventually sells his invention of an improved ticker tape machine to Taggart and Powell for $40,000, enabling him to get married and open his own laboratory at Menlo Park.

Edison “leaves science behind”, and with a Herculean trial-and-error effort, finally succeeds in inventing a practical electric light.

His subsequent plans to light New York City are again hindered by Taggart, who arranges it so that Edison is given only six months to complete the entire task.

It means home, shelter, clothing, and food for lots of families.” “He hasn’t got a darn thing but I like to hear him talk that way.” Bosley Crowther of The New York Times praised Tracy's performance for bringing "human and vital substantiality" to the role, but criticized the film for its numerous historical inaccuracies: "When Metro deliberately distorts certain important details in Edison's career and boldly invents others—even though it were done with the sanction of his family—the question arises as to whether this creation is intended to be a reliable portrait of the great inventor or just another fellow who looks something like him.

"[6] Film Daily called it "one of the truly memorable pictures of the year" and predicted it would "command most serious consideration" when it came time to vote for the Academy Awards.

[7] John Mosher of The New Yorker wrote that even though the story of Edison's career was "not really screen material ... more than one might think, its interest mounts with the advance of the picture and some actual excitement is achieved at last.