Sacheen Littlefeather, Native American activist, actress known for 1973 Oscar's speech dies at 75

Sacheen Littlefeather, the Native American actress and activist most widely known for rejecting Marlon Brando's Best Actor award at the 1973 Oscar's, has died at the age of 75, according to The Academy of Motion Picture Arts and Sciences.

Nearly 50 years ago, Brando sent Littlefeather to the stage of the 45th Academy Awards, after it was announced Brando had one the Best Actor award for his role in "The Godfather." In her speech rejecting the award, Littlefeather said Brando couldn't accept the award due to "the treatment of American Indians today by the film industry." She was booed.

Just last month, the Academy issued Littlefeather an apology for the treatment she received that night and afterwards, both in the form of a letter from former Academy president David Rubin, and in an in-person "healing event" at the Academy Museum.

"The abuse you endured because of this statement was unwarranted and unjustified," Rubin told Littlefeather at the event, reading from the letter he'd sent to her in June. "You are forever, respectfully, ingrained in our history."

SUGGESTED: Sacheen Littlefeather, booed at 1973 Oscar ceremony, gets in-person apology

Littlefeather was known for her roles in the 1973 film "The Trial of Billy Jack" and 1975's "Johnny Firecloud."

The Academy announced Littlefeather's passing on Twitter Sunday night, but no information about how she died was made available. 

Littlefeather was 75 years old.