Beloved American poet, activist, and educator Maya Angelou has died at age 86, after a recent undisclosed illness. The CBC reports that Angelou was scheduled to attend last Friday’s luncheon for the 2014 Major League Baseball Beacon Awards, where she was to be honoured. However, she apparently cancelled at the last minute due to health issues.

Born in St. Louis, Missouri, in 1928, Angelou was best known for her 1969 autobiographical work I Know Why the Caged Bird Sings (“A bird doesn’t sing because it has an answer, it sings because it has a song”), which became a bestseller, something virtually unheard of for a black woman in America at the time.

Less well known is Angelou’s early life, which includes studying dance with Martha Graham and touring with a production of Porgy and Bess. She appeared on film and television, including roles in the John Singleton film Poetic Justice and the classic television adaptation of Alex Haley’s trailblazing slavery novel Roots. She also made regular appearances on The Oprah Winfrey Show, which was largely responsible for introducing her to an even wider audience.

Angelou was an early supporter of Hillary Clinton for the Democratic nomination in 2008, but switched her support to Barack Obama after Clinton withdrew from the race. Underlining the problems that continue to persist in America around the issue of racial equality, Angelou told the Guardian in 2009 that she never thought the U.S. would elect a black man president. “In 100 years’ time or maybe 50…. But not now, no. I did not believe it could happen now.”

The Globe and Mail obituary recounts Angelou’s upbringing, which was plagued with violence and racially motivated hatred, causing her to completely reinvent herself as an adult:

Her very name as an adult was a reinvention. Angelou was born Marguerite Johnson in St. Louis and raised in Stamps, Ark., and San Francisco, moving back and forth between her parents and her grandmother. She was smart and fresh to the point of danger, packed off by her family to California after sassing a white store clerk in Arkansas. Other times, she didn’t speak at all: At age seven, she was raped by her mother’s boyfriend and didn’t speak for years. She learned by reading, and listening.

Angelou developed into a fierce advocate for civil rights and equality, enacting in her writing her belief that change comes not through silence, but through strenuous vocalization. And she remained committed to enacting change in others, right to the end of her career. “I’ve learned that people will forget what you said,” she claimed, “people will forget what you did, but people will never forget how you made them feel.”