How does Walker deal with race and gender in In Search of Our Mothers' Gardens?

In this essay, Alice Walker looks to the words of Virginia Woolf as she contemplates the unfulfilled dreams of women and of African-American women specifically throughout history:

Any woman born with a great gift in the sixteenth century would certainly have gone crazed, shot herself, or ended her days in some lonely cottage outside the village, half witch, half wizard, feared and mocked at. For it needs little skill and psychology to be sure that a highly gifted girl who had tried to use her gift of poetry would have been so hindered and thwarted by contrary instincts that she must have lost her health and sanity to a certainty.

Walker considers the women throughout history who might have been some of the greatest artists who walked the earth: the poets, sculptors, writers, artists. But because they were women (and some of them were doubly impacted by race), their dreams never came to fruition. No one allowed these women a means of creative expression. It is not that in the hundreds of years spanning American history that only now are women emerging with creative talents; this talent was passed through our mothers and grandmothers. Walker notes that walking around with so much creative genius and no means to express it must have driven some women insane, forcing their "minds to desert their bodies."
Walker does offer a hope of tracing the threads of creative genius that have lasted into our society today by first looking back at her own overworked mother's handiwork: sewing. Walker's mother stitched every article of clothing for her large family and quilted every blanket that kept them warm. Walker visited the Smithsonian and noted a gorgeous quilt depicting the Crucifixion with a simple note about the artist: "an anonymous Black woman in Alabama, a hundred years ago."
Here, then, is the link to the creative genius of women in America's past. These women used whatever medium they had access to as an outlet for their creativity: quilts, stories, flowers. Women and, more specifically, African-American women have been weaving their creativity into daily life throughout the history of America so that, like Walker, they can view life's difficulties:

through a screen of blooms-sunflowers, petunias, roses, dahlias, forsythia, spirea, delphiniums, verbena . . . and on and on.