In key aspects, the play closely parallels Eugene O'Neill's own life. The location, a summer home in Connecticut, corresponds to the family home Monte Cristo Cottage, in New London, Connecticut (the small town of the play). The actual cottage, today owned and operated by the Eugene O'Neill Theater Center, is made up as it may appear in the play. The family in the script corresponds to the O'Neill family, which was Irish-American, with three name changes. The family name "O'Neill" is changed to "Tyrone", which is the name of the earldom granted to Conn O'Neill by Henry VIII. The names of the second and third sons are reversed, "Eugene" with "Edmund". In fact, Eugene, the playwright, was the third and the youngest child, and he corresponds to the character of "Edmund" in the play. O'Neill's mother, Mary Ellen "Ella" Quinlan, corresponds to the character Mary Cavan. The ages are all the actual ages of the O'Neill family in August 1912.
Eugene O'Neill's father, James O'Neill, was a promising young actor in his youth, as was the father in the play. He also shared the stage with Edwin Booth, who is mentioned in the play. James O'Neill achieved commercial success in the title role of Dumas' The Count of Monte Cristo, playing the title role about 6,000 times, but he was criticized for "selling out" for commercial success at the expense of artistic merit.[8]
Eugene's mother Mary did attend Saint Mary's College, a Catholic school in the Midwest, of Notre Dame, Indiana. Subsequent to the date when the play is set (1912), but prior to the play's writing (1941–42), Eugene's older brother Jamie did drink himself to death (c. 1923).
Regarding O'Neill himself, by 1912 he had attended a renowned university (Princeton), spent several years at sea, and suffered from depression and alcoholism. He did contribute poetry to the local newspaper, the New London Telegraph, as well as reporting, and he was admitted to a sanatorium in 1912–13, suffering from tuberculosis (consumption), whereupon he devoted himself to playwriting. Thus, the events in the play are set immediately prior to O'Neill beginning his career in earnest.
