Question: In what year did Thornton Wilder write his three-act play that would later be compared to Neil Young's Greendale?

Context articles: The Seven Year Itch
Neil Young Journeys
Seven Days (play)
The Merchant of Yonkers
Janet Wilder Dakin
Our Town
Charlotte Wilder
Our Town (opera)
Greendale (album)
Hans Sahl

The Seven Year Itch is a 1955 American romantic comedy film based on a three-act play with the same name by George Axelrod.
 The film was co-written and directed by Billy Wilder, and stars Marilyn Monroe and Tom Ewell, reprising his Broadway role from the play.
 It contains one of the most notable images of the 20th century – Monroe standing on a subway grate as her white dress is blown upwards by a passing train.
 The titular phrase, which refers to declining interest in a monogamous relationship after seven years of marriage, has been used by psychologists.
Neil Young Journeys is a 2011 American concert documentary film produced and directed by Jonathan Demme, featuring Neil Young and produced for Sony Pictures Classics.
 It is, along with "" (2006) and "Neil Young Trunk Show" (2009), part of a Neil Young trilogy being created by Demme.
Seven Days is a three-act play written in 1909 by Avery Hopwood and Mary Roberts Rinehart.
 It is a farce based on Rinehart's 1908 novella of the same name, which had been expanded into a bestselling 1909 novel titled "When a Man Marries".
 Producers Lincoln Wagenhals and Collin Kemper staged the play at the Astor Theatre on Broadway, where it premiered on November 10, 1909.
 The production was a hit and led Hopwood to a highly successful career as an author of comedies.
 Rinehart and Hopwood would later collaborate on two other hit plays, "Spanish Love" and "The Bat".
The Merchant of Yonkers is a play by Thornton Wilder.
 The play had its origins in an 1835 one-act farce by the English dramatist John Oxenford.
 Oxenford's work, "A Day Well Spent", was later extended into a full-length play entitled "Einen Jux will er sich machen" ("He Will Go on a Spree" or "He'll Have Himself a Good Time") by Austrian playwright Johann Nestroy in 1842.
 Wilder adapted Nestroy's version into an Americanized comedy entitled "The Merchant of Yonkers", which revolves around Horace Vandergelder, a wealthy Yonkers, New York businessman in the market for a wife.
Janet Wilder Dakin (June 3, 1910 - October 7, 1994), was a philanthropist, zoologist and a younger sister of author Thornton Wilder and poet Charlotte Wilder.
Our Town is a 1938 metatheatrical three-act play by American playwright Thornton Wilder.
 It tells the story of the fictional American small town of Grover's Corners between 1901 and 1913 through the everyday lives of its citizens.
Charlotte Wilder (1898–1980) was an American poet and the eldest sister of author Thornton Wilder, Isabel Wilder, Janet Wilder Dakin, and Amos Wilder.
Our Town is a three-act opera by composer Ned Rorem and librettist J. D. McClatchy.
 It is the first opera to be adapted from the Thornton Wilder play of the same name.
 The opera was commissioned by Indiana University, Opera Boston, the Aspen Music Festival and School, North Carolina School of the Arts, Lake George Opera in Saratoga Springs, N.Y., and Festival Opera in Walnut Creek, Calif.
Greendale is the twenty-sixth studio album by Neil Young.
 Young and Crazy Horse's "Greendale", a 10-song rock opera, is set in a fictional California seaside town.
 Based on the saga of the Green family, the "audio novel" has been compared to the literary classics of Thornton Wilder's "Our Town" and Sherwood Anderson's "Winesburg, Ohio" for its complexity and emotional depth in exploring a small town in America.
Hans Sahl (born Hans Salomon in Dresden on 20 May 1902; died in Tübingen on 27 April 1993) was a poet, critic, and novelist who began during the Weimar Republic.
 He came from an affluent Jewish background, but like many such German Jews he fled Germany due to the Nazis.
 First to Czechoslovakia in 1933, then to Switzerland, and then France.
 In France he was interned along with Walter Benjamin.
 He would later flee Marseille and work with Varian Fry to help other artists or intellectuals fleeing Nazism.
 He became known as one of the anti-fascist exiles and in the US translated Arthur Miller, Thornton Wilder, and Tennessee Williams into German.