There is uncertainty as to McKay's age - Wikipedia says she was "probably born between 1931 and 1947 [!], according to colleagues" - but none as to her influence.
The daughter of Jamaican immigrants, McKay got a masters and Ph.D. from Harvard before joining the UW-Madison in 1978. She turned down an offer to become Harvard's head of African American studies; the job went instead to Henry Louis Gates, with whom she later coedited the 2,665-page Norton Anthology of African American Literature, published in 1996.
McKay blazed a trail for African American literature and especially black women writers, like Toni Morrison. "When she came here, there was not a single university that was paying any attention to black women's literature," mused a UW colleague, Craig Werner, after McKay's death in 2006. "Now there isn't a single university that isn't."