Maya Angelou, whose landmark book of 1969, “I Know Why the Caged Bird Sings” — a lyrical, unsparing account of her childhood in the Jim Crow South — was among the first autobiographies by a 20th-century black woman to reach a wide general readership, died on Wednesday at her home in Winston-Salem, N.C. She was 86.

Her death was confirmed by her literary agent, Helen Brann. The cause was not immediately known, but Ms. Brann said Ms. Angelou had been frail for some time and had heart problems.

In a statement, President Obama said, “Today, Michelle and I join millions around the world in remembering one of the brightest lights of our time — a brilliant writer, a fierce friend and a truly phenomenal woman,” adding, “She inspired my own mother to name my sister Maya.”

Though her memoirs, which eventually filled six volumes, garnered more critical praise than her poetry did, Ms. Angelou (pronounced AHN-zhe-low) very likely received her widest exposure on a chilly January day in 1993, when she delivered her inaugural poem, “On the Pulse of Morning,” at the swearing-in of Bill Clinton, the nation’s 42nd president. He, like Ms. Angelou, had grown up in Arkansas.