Alexander Graham Bell falls in love with deaf girl Mabel Hubbard while teaching the deaf and trying to invent means for telegraphing the human voice. She urges him to put off thoughts of marriage until his experiments are complete. He invents the telephone, marries and becomes rich and famous, though his happiness is threatened when a rival company sets out to ruin him.
Don Ameche
as Alexander Graham Bell
Loretta Young
as Mrs. Mabel Hubbard Bell
Henry Fonda
as Thomas Watson
Charles Coburn
as Gardner Hubbard
Gene Lockhart
as Thomas Sanders
Spring Byington
as Mrs. Hubbard
Sally Blane
as Gertrude Hubbard
Polly Ann Young
as Grace Hubbard
Georgiana Young
as Berta Hubbard
Bobs Watson
as George Sanders
Russell Hicks
as Mr. Barrows
Paul Stanton
as Chauncey Smith
