The tragedy Long Day's Journey into Night is often included on lists of the finest U.S. plays in the 20th century, alongside Tennessee Williams's A Streetcar Named Desire and Arthur Miller's Death of a Salesman.

His father suffered from alcoholism; his mother from an addiction to morphine, prescribed to relieve the pains of the difficult birth of Eugene, who was her third son.

[7] Because his father was often on tour with a theatrical company, accompanied by Eugene's mother, in 1895 O'Neill was sent to St. Aloysius Academy for Boys, a Catholic boarding school in the Riverdale section of the Bronx.

[15] O'Neill's parents and elder brother Jamie (who drank himself to death at the age of 45) died within three years of one another, not long after he had begun to make his mark in the theater.

In the fall of 1914, he entered Harvard University to attend a course in dramatic technique given by George Piece Baker, but left after one year.

[9] During the 1910s O'Neill was a regular on the Greenwich Village literary scene, where he also befriended many radicals, most notably Communist Labor Party of America founder John Reed.

O'Neill's first published play, Beyond the Horizon, opened on Broadway in 1920 to great acclaim, and was awarded the Pulitzer Prize for Drama.

His first major hit was The Emperor Jones, which ran on Broadway in 1920 and obliquely commented on the U.S. occupation of Haiti that was a topic of debate in that year's presidential election.

[21] In 1936, O'Neill received the Nobel Prize in Literature after he had been nominated that year by Henrik Schück, member of the Swedish Academy.

[27] The years of their marriage—during which the couple lived in Connecticut and Bermuda and had two children, Shane and Oona—are described vividly in her 1958 memoir Part of a Long Story.

They divorced on July 2, 1929, after O'Neill abandoned Boulton and the children, for the actress Carlotta Monterey (born San Francisco, California, December 28, 1888; died Westwood, New Jersey, November 18, 1970).

[28] In 1929, O'Neill and Monterey moved to the Loire Valley in central France, where they lived in the Château du Plessis in Saint-Antoine-du-Rocher, Indre-et-Loire.

During the early 1930s they returned to the United States and lived in Sea Island, Georgia, at a house called Casa Genotta.

Shane O'Neill became a heroin addict and moved into the family home in Bermuda, Spithead, with his new wife, where he supported himself by selling off the furnishings.

[citation needed] While at Tao House, O'Neill had intended to write a collection of works he called "the Cycle" chronicling American life spanning from 1755 to 1932.

[30] As his health worsened, O'Neill lost inspiration for the project and wrote three largely autobiographical plays, The Iceman Cometh, Long Day's Journey into Night, and A Moon for the Misbegotten, which he completed in 1943, just before leaving Tao House and losing his ability to write.

In 1956, Carlotta arranged for his autobiographical play Long Day's Journey into Night to be published, although his written instructions had stipulated that it not be made public until 25 years after his death.

In 2000, a team of researchers studying O'Neill's autopsy report concluded that he died of cerebellar cortical atrophy, a rare form of brain deterioration unrelated to either alcohol use or Parkinson's disease.

[33] In Warren Beatty's 1981 film Reds, O'Neill is portrayed by Jack Nicholson, who was nominated for the Academy Award for Best Supporting Actor for his performance.

His home in Danville, California, near San Francisco, was preserved as the Eugene O'Neill National Historic Site in 1976.

The Eugene O'Neill Theatre has housed musicals and plays such as Yentl, Annie, Grease, M. Butterfly, Spring Awakening, and The Book of Mormon.