Rich died Tuesday at home from complications from rheumatoid arthritis, said her son, Pablo Conrad. She had lived in Santa Cruz since the 1980s.
Through her writing, Rich explored topics such as women’s rights, racism, sexuality, economic justice and love between women.
Rich published more than a dozen volumes of poetry and five collections of nonfiction. She won a National Book Award for her collection of poems Diving into the Wreck in 1974. In 2004, she won the National Book Critics Circle Award in Poetry for her collection The School Among the Ruins.
According to her publisher, W.W. Norton, her books have sold between 750 000 and 800 000 copies, a high amount for a poet.
She gained national prominence with her third poetry collection, Snapshots of a Daughter-in-Law, in 1963. Citing the title poem, University of Maryland professor Rudd Fleming wrote in The Washington Post that Rich "proves poetically how hard it is to be a woman – a member of the second sex".
Rich and her husband had three sons before she left him in 1970, just as the women’s movement was exploding on the national scene. She used her experiences as a mother to write Of Woman Born, her groundbreaking feminist critique of pregnancy, childbirth and motherhood, published in 1976.
Unlike most American writers, Rich believed that art and politics not only could co-exist, but must co-exist. She considered herself a socialist because "socialism represents moral value – the dignity and human rights of all citizens," she told the San Francisco Chronicle in 2005. "That is, the resources of a society should be shared and the wealth redistributed as widely as possible."
"She was very courageous and very outspoken and very clear," said her longtime friend, W.S. Merwin, the Pulitzer Prize winning poet. "She was a real original, and whatever she said came straight out of herself."
Rich taught at many colleges and universities, including Brandeis, Rutgers, Cornell, San Jose State and Stanford.
She won a MacArthur "genius" fellowship, two Guggenheim Fellowships and many top literary awards including the Bollingen Prize, Brandeis Creative Arts Medal, Ruth Lilly Poetry Prize and the Wallace Stevens Award.
But when then-President Clinton awarded the National Medal of Arts in 1997, Rich refused to accept it, citing the administration’s "cynical politics."
"The radical disparities of wealth and power in America are widening at a devastating rate," she wrote to the administration. "A president cannot meaningfully honour certain token artists while the people at large are so dishonoured."
In 2003, Rich and other poets refused to attend a White House symposium on poetry to protest to US-led invasion of Iraq.
Born in Baltimore in 1929, Rich was the elder of two daughters of a Jewish father and a Protestant mother – a mixed heritage that she recalled in her autobiographical poem Sources. Her father, a doctor and medical professor at Johns Hopkins University, encouraged her to write poetry at an early age.
Rich graduated from Radcliffe College in 1951 and was chosen for the Yale Younger Poets Prize for her first book of poetry, A Change of World.
Living in Cambridge, Massachusetts, she befriended Merwin, Donald Hall and other poets. In 1953, she married Harvard University economist Alfred Conrad. In 1966, her family moved to New York City when her husband accepted a teaching position at City College.
Rich taught remedial English to poor students entering college before teaching writing at Swarthmore College, Columbia University School of the Art and City University of New York.
After she left her husband, he committed suicide. She later came out as a lesbian and lived with her partner, writer and editor Michelle Cliff.