Rabbi Cominsky, the father of two sons, ekes out a living in New York's Lower East Side as a pushcart peddler. He favors the studious and ambitious Morris, the elder, who wants to be a lawyer, rather than the loyal Sammy, who sells papers and who helps put his older brother through college. Cominsky finds out that Sammy has become a prizefighter under the name "Battling Rooney" and drives him out of the house. Morris demands that his father buy him a dress suit, so Cominsky pawns his overcoat to get one (which Morris throws in an ashcan) and becomes seriously ill from exposure to the cold. Cominsky passes the crisis but is told he must go to a warmer climate. Morris, meanwhile, has become engaged to marry Ruth Stein, his boss's daughter, but is ashamed of his parentage. Cominsky arrives at the engagement party, and Morris refuses to acknowledge his own father. Sammy, after winning the lightweight championship, faces up to his brother, denounces him, and drags him home. Morris, realizing his sin, begs and receives forgiveness. Cominsky acknowledges his gratitude to Sammy and gives his blessing to Sammy's Irish sweetheart, Mamie.