"Long Day's Journey Into Night" is a semi-autobiographical play by Eugene O'Neill, first published in 1956. The story unfolds over a single day in the life of the Tyrone family, revealing their struggles with addiction, illness, and interpersonal conflict. The characters include James Tyrone, a financially successful but emotionally distant father, his morphine-addicted wife Mary, and their two sons, Jamie and Edmund, who grapple with their own demons. The play explores themes of family dysfunction, the impact of the past, and the search for redemption. Set in the early 20th century, it reflects O'Neill's own experiences and offers a poignant look at the complexities of familial love and pain. The raw emotional depth and realism have made it a significant work in American theater.