Written in 1941-1942 and first published in 1956, Long Day's Journey into Night is a tragedy in four acts. The play is semi-autobiographical. It is widely considered to be Eugene O'Neill’s magnum opus and one of the finest American plays of the 20th century. The "Long Day" refers to the setting of the play, which takes place during a single day in August 1912, from around 8:30 a.m. to midnight. The story revolves around the Tyrone family consisting of father James (an actor), mother Mary (a morphine addict), and their sons Jamie and Edmund.