Sullavan preferred working on the stage and made only 16 films, four of which were opposite close friend James Stewart in a popular partnership that included The Mortal Storm and The Shop Around the Corner.

After her recovery she emerged as an adventurous and tomboyish child who preferred playing with children from a poorer neighborhood, much to the disapproval of her class-conscious parents.

[8] Sullavan made her debut on Broadway in A Modern Virgin (a comedy by Elmer Harris) on May 20, 1931, and began touring on August 3.

[6] At one point in 1932, she starred in four Broadway flops in a row (If Love Were All, Happy Landing, Chrysalis (with Humphrey Bogart), and Bad Manners), but the critics praised Sullavan for her performances in all of them.

In his November 10, 1933, review in The New York Herald Tribune, Richard Watts, Jr. wrote that Sullavan "plays the tragic and lovelorn heroine of this shrewdly sentimental orgy with such forthright sympathy, wise reticence and honest feeling that she establishes herself with some definiteness as one of the cinema people to be watched.

In the comedy The Moon's Our Home (1936), Sullavan played opposite her ex-husband Henry Fonda as a newly married couple.

[citation needed] In The Shop Around the Corner (1940), Sullavan and Stewart worked together again, playing colleagues who unknowingly exchange letters with each other.

Back Street (1941) was lauded as among the best performances of Sullavan's Hollywood career, a film for which she ceded top billing to Charles Boyer to ensure that he would take the male lead part.

[18] So Ends Our Night (1941) was a wartime drama in which Sullavan, on loan to United Artists for a one-picture deal from Universal, played a Jewish exile fleeing the Nazis.

A 1940 court decision obligated Sullavan to fulfill her original 1933 agreement with Universal, requiring her to appear in two more films for the studio.

"[20] The script contained a role that she thought might be ideal for Stewart, who was the best friend of Sullavan's first husband, actor Henry Fonda.

Years earlier, during a casual conversation with some fellow actors on Broadway, Sullavan predicted that Stewart would become a major Hollywood star.

The inexperienced Stewart had been nervous and unsure of himself during the early stages of production, and director Edward H. Griffith, began bullying him.

[22] However, Sullavan believed in Stewart and spent evenings coaching him and helping him scale down his awkward mannerisms and hesitant speech that were soon to be famous.

[24] When Sullavan divorced Wyler in 1936 and married Leland Hayward that same year, they moved into a colonial house just a block away from that of Stewart.

"[27] Sullavan and Stewart appeared in four films together between 1936 and 1940 (Next Time We Love, The Shopworn Angel, The Shop Around the Corner and The Mortal Storm).

"[28] Another reason for her early retirement from the screen (1943) was that she wanted to spend more time with her children, Brooke, Bridget and Bill (then 6, 4 and 2 years old).

From 1943 to 1944, she played the sexually inexperienced but curious Sally Middleton in The Voice of the Turtle (by John Van Druten) on Broadway and later in London (1947).

She played a suburban housewife and mother who learns that she will die of cancer within a year and who then determines to find a "second" wife for her soon-to-be-widower husband (Wendell Corey).

After No Sad Songs for Me and its favorable reviews, Sullavan had a number of offers for other films, but she decided to concentrate on the stage for the rest of her career.

Her choice then was as the suicidal Hester Collyer, who meets fellow sufferer Mr. Miller (played by Herbert Berghof) in Terence Rattigan's The Deep Blue Sea.

At age 22, she married actor Henry Fonda on December 25, 1931, while both were performing with the University Players in their 18-week winter season at the Congress Hotel ballroom in Baltimore, Maryland.

[38] In 1955, when Sullavan's two younger children told their mother that they preferred to stay with their father permanently, she suffered a nervous breakdown.

"[39] In another scene from the book, a friend of the family (Millicent Osborne) had been alarmed by the sound of whimpering from the bedroom: "She walked in and found Mother under the bed, huddled in a fetal position.

"[citation needed] Sullavan had an operation done by Dr. Julian Lempert in the late 40s, which Brooke described as a “success, and restored full hearing to Mother’s left ear,” but she didn't follow his advice for cutting down on “diving, shooting or flying.”[43] Sullavan bequeathed her ears to the Lempert Institute of Otymology.

Her copy of the script to Sweet Love Remembered, in which she was then starring during its tryout in New Haven, was found open beside her, as well as a bottle of prescribed pills.

No note was found to indicate suicide, and initially no conclusion was reached as to whether her death was the result of a deliberate or an accidental overdose of barbiturates.

[48] After a private memorial service in Greenwich, Connecticut, with such attendees as former friend and co-star Joan Crawford, theatre producer Martin Gabel, and actress Sandra Church, Sullavan was interred at Saint Mary's Whitechapel Episcopal Churchyard in Lancaster, Virginia.

[49] For her contribution to the motion picture industry, Margaret Sullavan has a star on the Hollywood Walk of Fame at 1751 Vine Street.

Brooks wrote this: "After he left her to marry Nancy (Slim) Hawks in 1947, this terrifyingly self-willed woman shredded her career through the following twelve years with her struggle to repossess him.