Stream A Son of Erin Online Free – Watch Full Movie from Home at 123Movies. . Dennis O'Hara is a poverty-stricken Irishman who believes that if he comes to America he will immediately land a job as a policeman. So he manages to scrape together the funds to get him to Manhattan, and leaves his sweetheart Katie O'Grady behind while he makes his fortune. Naturally he discovers that joining the force isn't as easy as he expected, and when he does finally get in, he winds up in trouble because of the graft collections of his boss.