The Pleznik family from Hungary arrives in New York -- after landing at Ellis Island, the parents, Peter (Rudolph SChildkraut) and Louise (Marie Dresser), and their three children settle on the Lower East Side of Manhattan and, with with help from a nice policeman, find their way to the home of an old friend. Peter Pleznik and his family are happy to be in America, but they soon cross paths with an malcontent named Sokol (Fritz Feld), who warns them that they will never find happiness in America, and rails against the government. But Peter Pleznik won't hear anything of it -- he even takes the presence of a roach in his apartment as a memory of home from Hungary; and, a talented trombonist he, he strikes up a friendship with a more amateur player from across the airshaft, and they join in a duet of "Yankee Doodle Dandy." And he manages to get a job, with help from his new friend, as a janitor in the Federal Building downtown. But not all goes well for the family -- Peter's son is forced to fight when he's attacked on the street, but he does win the fight; and Peter finds his own boss isn't much less prejudiced than the thug his son met. But Peter proudly puts up a picture of his "new boss," as he calls him, President Woodrow Wilson. He loves his job in the government building, and is moved to tears when he accidentally glimpses a group of immigrants taking their oaths of citizenship. He makes the acquaintance of Judge Gresham, who gives him the information he needs to become a citizen. Five years go by, and Peter is about to take his oath of citizenship, and his son Eric, now 18, is planning on joining the United States Army. Meanwhile, Sokol's hatred for the United States, and decides to take action against the sentencing judge when a fellow foreign-born malcontent guilty of treasonous activity is sentence to 10 years in prison. And the man against whom he is plotting is Judge Gresham, who has become Peter's friend during the five years he has worked at the courthouse; Peter takes his oath of citizenship from the judge in private, and he and the judge share a cigar. But Sokol is in the courthouse waiting for his chance, and manages to implicate Peter in the subsequent bombing. He is nearly destroyed by the ensuing events as he finds himself accused, and only his faith in the United States sustains him.