Margaret Manning, a poor waif whose mother was claimed by death early in her childhood, and whose father, machine politician Jim Connelly, deserted her, is raised by the Finns, a poor family who send her into the factory. The evils of such a life make a deep impression on Margaret, who attends night school to better herself. Assuming the leadership in a campaign to abolish child labor, Margaret journeys to Washington where she falls in love with Jack West, the son of a wealthy politician. Margaret's bill is backed by Senator Mathews, who decides to discredit his opponent, Jim Connelly, by investigating his past. He discovers that Margaret is Connelly's daughter, a fact that shakes Jack's faith in her. However, when Connelly finally admits that he is beaten and praises his daughter's tenacity, Jack's faith is restored, and the bill is passed to the benefit of thousands of factory workers.