In 1871 Chicago, honest lawyer Jack (Don Ameche) and his reckless saloon owner brother Dion (Tyrone Power) are two very different men attracted to the same beautiful singer, Belle (Alice Faye). Personally and professionally at odds, their relationship is tested as Jack becomes mayor of Chicago, while his brother becomes a leader in disreputable entertainments. Their conflict culminates in the Great Chicago Fire, started by a cow belonging to their mother, Mrs. O'Leary (Alice Brady).