Maya Angelou, the celebrated poet, writer and activist who rose from a childhood of poverty in Arkansas to become an American literary icon, died Wednesday morning at her home in Winston-Salem, N.C., at the age of 86.

Born in 1928 as Marguerite Johnson, Ms. Angelou led a multitude of lives. She drove a streetcar in San Francisco, was a newspaper editor in Egypt and worked as a cook and a prostitute when she was a destitute single mother. She wrote television and movie screenplays, performed on the stage as a singer, dancer and actor and released an album of Calypso music.

But Ms. Angelou will be remembered above all as the "people's poet," a towering public figure and literary icon whose words seem to appear everywhere—spoken at a presidential inauguration, stamped on Hallmark greeting cards and, on the day she died, cascading on Twitter and Facebook as millions commemorated her life and work.

Ms. Angelou was busy writing and planning public appearances in her final days. She was scheduled to receive an award in Houston on Friday but canceled her appearance, citing a health emergency.

Helen Brann, Ms. Angelou's agent of close to 35 years, said the poet was in the middle of writing a new book and was in good spirits when they spoke on Tuesday.