O’Neill conceived of creating a modern psychological drama rooted in Greek legend in the spring of 1926, but Mourning Becomes Electra was not completed until the spring of 1931. Actually a trilogy of three full-length plays, it opened in October and was deemed a masterpiece by more than one critic. O’Neill said: “By the title Mourning Becomes Electra I sought to convey that mourning befits Electra; it becomes Electra to mourn; it is her fate; black is becoming to her and it is the color that becomes her destiny.”

The Greek source for O’Neill was the Oresteia of Aeschylus, from the fifth century b.c.e., the trilogy detailing the relationships of the house of Atreus. In the first play, after the siege of Troy, Clytemnestra murders her husband, the victorious Agamemnon; in the second, their son Orestes, with his sister Electra, murders his mother and her lover Aegisthus; in the third, Orestes is hounded by the Furies for matricide but is eventually freed from his guilt and acquitted of the crime. O’Neill reworked much of this story; he also drew upon the versions of Electra by Sophocles and Euripides, which focus upon the daughter, a haunted woman, torn by hate and love and never at peace.

The Mannon family (the name may be associated with “mammon” and the family’s materialism) is the center of O’Neill’s play, which is set in New England immediately after the Civil War. The house is described in the stage directions as resembling a white Greek temple, with six columns across the front porch. In the first play, The Homecoming, Christine Mannon (Clytemnestra) has taken a lover, Adam Brant (Aegisthus), while her husband, Ezra (Agamemnon), has been fighting in the war. Daughter Lavinia (Electra) is jealously aware of the affair and threatens her mother with exposure. In this section, mother and daughter are rivals for the love of Ezra and Adam.

When Ezra returns, Lavinia desperately tries to win his love and attention from her mother, as Ezra makes an impassioned effort to communicate with Christine, begging her to love him. Thinking only of her lover, she rejects him, and when he has a heart attack, she administers poison rather than medicine. In his death throes, he reveals Christine’s crime to Lavinia.

The triangular structure of the second play, The Hunted, includes Lavinia, Christine, and the newly returned battle-scarred Orin (Orestes). Each woman is...