For her portrayal of Emma Goldman in the historical epic film Reds (1981) she received the Academy Award for Best Supporting Actress.

[7][8] Stapleton moved to New York City at the age of 18, and worked as a salesgirl, hotel clerk, and modeled to pay the bills, including for artist Raphael Soyer.

That same year, she played the role of "Iras" in Shakespeare's Antony and Cleopatra in a touring production by actress and producer Katharine Cornell.

[citation needed] Stapleton played in other Williams' productions, including Twenty-Seven Wagons Full of Cotton and Orpheus Descending (and its film adaptation, The Fugitive Kind, co-starring her friend Marlon Brando), as well as in The Cold Wind and the Warm (Tony nomination, 1959) and Lillian Hellman's Toys in the Attic (1960), for which she received another Tony Award nomination.

Later Broadway roles included a Tony-nominated turn as "Birdie" in The Little Foxes, opposite Elizabeth Taylor, and as a replacement for Jessica Tandy in The Gin Game.

She won the Best Supporting Actress Oscar for Reds (1981), directed by Warren Beatty, in which she portrayed the Lithuanian-born anarchist, Emma Goldman.

Stapleton won a 1968 Emmy Award for her performance in Among the Paths of Eden and was nominated for six more, for Avonlea (1996), Miss Rose White (1992), B.L.

[13] She was an alumna of the famous Actors Studio in New York City, led by Lee Strasberg, where she became friends with Marilyn Monroe, who was only one year younger than Stapleton.

Stapleton's first husband was Max Allentuck, general manager to the producer Kermit Bloomgarden, and her second was playwright David Rayfiel, from whom she divorced in 1966.

[20] A lifelong heavy smoker, Stapleton died of chronic obstructive pulmonary disease in 2006 at her home in Lenox, Massachusetts.

[9] In 1981 Hudson Valley Community College in Stapleton's childhood city of Troy, New York, dedicated a theater in her name.