The two "O'Leary" brothers grow up without their father in an house where their widowed mother runs quite a successful laundry business. One son, "Jack" (Don Ameche), shows promise as a lawyer; the other "Dion" (Tyrone Power) is a more inventive sort of fella. After a few, quite entertaining wooing antics, the latter hooks up with visiting chanteuse "Belle" (Alice Faye) and together they start a business that rapidly expands so as to soon dominate the rather rundown "Patch" area of Chicago. The city government is riddled with corruption and so a group of civil libertarians nominate brother "Jack" to be mayor - a plan supported, for other reasons, by his now very wealthy sibling. It's only a matter of time before the two clash - but who will prevail? Power is charming and engaging here, he has a twinkle in his eye and there is certainly some chemistry between him and Faye. The ending, though impressive to watch with all the pyrotechnics of the Great Fire of 1871 that devoured thousands of the predominantly wooden structures of the area, is all a bit hurried and weak. The more interesting political and personal struggles between the two men, and agitator "Warren" (Brian Donlevy) should have featured more, with less emphasis on the initial character development and I could have done without the musical numbers that though ably enough performed by Faye, just sucked too much of the pace of this Cain and Abel style of story. Still, it's enjoyable to watch and gives us a hint at just how corruption and power-brokering functioned back then.