Isadore Goldberg, an enterprising Russian Jew, comes to the United States and establishes himself in the delicatessen business so that he can one day send for his parents. Forced to vacate his store, Izzy relocates in an Irish neighborhood; there, after he changes his surname to "Murphy," his business prospers. While waiting for a subway train, Izzy recovers a girl's handkerchief; later, he meets her in his store and learns that she is Eileen Cohannigan, from whose father he buys foodstuffs. After the arrival of Izzy's parents, he embarks for France with an all-Irish regiment and inspires his comrades to deeds of valor. He is welcomed home by Cohannigan, but when Cohannigan learns that he is Jewish, he denounces his daughter for loving him. With the aid of his service buddies, however, Izzy and Eileen head for City Hall to be married.