On the Lower East Side of Manhattan in the early years of the twentieth century, a Jewish family struggles to survive -- David Cominsky (Rudolph Schildkraut), who was a man of learning and a teacher in Russia, ekes out a living from his pushcoart, selling the little items that his wife Rose (Rosa Rosanova) toils to make at home, so that their two sons, Morris and Sammy, can have a better life. Morris, the older, likes to study, almost to the exclusion of much else; and Sammy, the younger, is always getting into fights and, as David says, is either going to commit murder or become a prize-fighter (which may be worse). When Sammy gets a dollar from a local tout (Edgar Kennedy) for winning a fight with a bigger boy who was picking on his brother, David is furious -- but it earns Sammy the admiration of Mamie Shannon, the girl who lives in the next apartment over. By the time they're in their early 20's, both boys are moving into the bigger world beyond the ghetto, and are also forced to hide aspects of their new lives from their parents -- and visa versa. Morris (Arthur Lubin) is an attorney and an associate in a law firm, with lots of friends uptown; his employer, former judge Nathan Stein (Bertram Marburgh), even sees him as a potential fiance for his daughter Ruth (Virginia Brown Faire); but he is also doing his best to hide his Lower East Side background from his more worldly friends, claiming he is an orphan; and Sammy (George Lewis) is getting ready to go into the ring professionally, under the name "Battling Rooney," and has been stepping out with Mamie (Blanche Mehaffey). When he learns of Sammy's secret fighting, David is devastated by the fact that one of his sons should become a boxer and throws him out of the house; and when Morris announces that he is leaving home, to live uptown in order to further his career, the Cominsky parents feel as though they've lost a part of themselves. David keeps at his pushcart, scratching out a living even in the dead of winter -- meanwhile, Rose secretly visits Sammy to watch out for him, and he secretly gives her money. When Morris arrives one day to say that he needs money for a dress suit, David sells the coat that that has kept him warm through winters going back to Russia, to buy him a suit -- which Morris throws away in disdain as soon as he leaves their home; but in running his errand, David has caught pneumonia, and Morris neglects to come to see him -- Sammy arrives and pretends to be his older brother, and the subterfuge helps get his father through; in the process, he also decides to settle down and marry Mamie. But now David needs to move to someplace warmer and more hospitable than New York, such as California -- Sammy decides to return to the ring with his old manager when the latter loses his best fighter on the eve of a championship match. On the same night that Sammy is fighting his heart out to help his father, David learns that Morris has abandoned the family, and multiple confrontations ensue as proud old man finally starts to see the truth about both of his sons and his own mistakes.