“I don’t want to make somebody else,” Toni Morrison’s character Sula declares, when urged to get married and have kids, “I want to make myself.” Morrison herself might have understood this to be a false dichotomy—she was a single mother of two by the time she published “Sula,” her second novel, in 1973—but, in her fiction, she split the individualist impulse to make an artful life and the domestic drive to make a home between two characters: Sula and her best friend, Nel. The tensions between these two desires animate the body of fiction and nonfiction about the private lives of women and mothers. It’s a canon that has been dominated by the accounts of white, straight writers, but it now includes Michelle Obama’s blockbuster memoir, “Becoming.”

What Obama brings to this genre is, first, a powerful sense of self, which precedes and exceeds her domestic relationships—the book’s three sections are titled “Becoming Me,” “Becoming Us,” “Becoming More”—and, second, a conviction that the roles of wife and mother are themselves undefined. She makes and remakes her relationship to both throughout her adult life. In this, she draws on the literature of black women’s self-making that “Sula” represents. The modern matron saint of that tradition is Zora Neale Hurston, who, in a 1928 essay, describes “How It Feels to Be Colored Me”: a prismatic, mutable experience of being a loner, a spectacle, an ordinary woman, a goddess (“the eternal feminine with its string of beads”). Lucille Clifton shares Hurston’s sense of the need to invent oneself in a world without reliable mirrors or maps; as she writes in a poem, from 1992, “i had no model. / born in babylon / both nonwhite and woman / what did I see to be except myself? / i made it up…” Like these writers, Obama exposes the particular pressures and thrills of black women’s self-creation. But she also details the rather more modest creation of a stable domestic life. By bringing motherhood, marriage, and self-making together in “Becoming,” she combines the possibilities that Sula and Nel represent.

In some ways, Obama’s desires for a stable home and family are quite conventional, and she uses the conventionally feminine, domestic metaphor of knitting to describe them. “We were learning to adapt, to knit ourselves into a solid and forever form of us,” she writes of the first months of her marriage to Barack. It isn’t easy: in the Robinson-Obama union, the South Side power-walker meets the Hawaii-born ambler; the meticulous planner and striver with an “instinctive love of a crowd” and a desire for family must adapt to the messy, cerebral dreamer who loves solitude and books at least as much as he loves people. Later, the woman who loathes politics must throw her life into her husband’s pursuit of the Presidency.

Things are complicated long before the campaign, as children both complete and unsettle the Obamas’ carefully cultivated “us.” Once Obama gets pregnant, through I.V.F., her resentment at Barack’s distance from the pain of miscarriage and needles gives way to feelings of maternal pride. Upon Malia’s arrival, she writes, “motherhood became my motivator”—yet, three years (and almost twenty pages) later, she is most galvanized by her new full-time job, at the University of Chicago Medical Center. Although she considers staying home when Sasha is born, she instead takes the job, which “[gets her] out of bed in the morning,” though Barack’s comparative absence, as a commuting state and U.S. senator, gets her home in time for dinner. Then, just as Sasha is about to start elementary school and Obama is “on the brink of . . . [firing] up my ambition again and [considering] a new set of goals,” it is decided that Barack should run for President.

Michelle is still driven, but now by a desire not to fail Barack’s growing base of supporters. In an effort to “earn” public approval, she talks a lot about her kids while campaigning—a safe subject for a black woman who was framed in negative contemporary press accounts as an unpatriotic shrew. As the Obamas near the Iowa primaries, Michelle’s growing commitment to Barack’s cause is reflected in her language. Her pronouns shift from “him” to “we”—“Our hopes were pinned on Iowa. We had to win it or otherwise stand down”—and she adopts Barack’s own sermonic listing mode, describing meetings with voters “in Davenport, Cedar Rapids, Council Bluffs . . . in bookstores, union halls, a home for aging military veterans, and, as the weather warmed up, on front porches and in public parks.” Her rhetoric itself knits her and Barack into a “we.”

The book as a whole, however, represents a different moment, and announces her ambition to tell her story in her own way. A long memoir by any measure, “Becoming” not only matches the length of Barack’s first book, “Dreams from My Father,” but it also shows Michelle to be a better storyteller than her husband—funnier, and able to generate a surprising degree of suspense about events whose outcomes are a given (the results of Barack’s first run for President, for instance). Having devoted herself to strategically remaking the office of First Lady, through such initiatives as the White House garden and Let Girls Learn, she now reflects on what she has done and who else she might want to become.

Of course, the choices she makes throughout—to focus more and less on work, more and less on family—are a function of privilege. It is a privilege to decide how much or whether to work, and a privilege to have children, whether through I.V.F. or otherwise. The ability to steer one’s own ship also relies on the sheer luck of evading any number of American disasters: layoffs, mass shootings, prison, domestic violence, lack of health care. Then there are the disasters perpetrated by the U.S. surveillance state, which can undo black women, such as Sandra Bland, or their children, such as Kalief Browder. Under these conditions of hypervisibility, no amount of strategic maneuvering can guarantee one’s safety. And, in light of this, the Obamas’ faith in the American system, and in electoral politics, can seem woefully insufficient.

It comes as something of a relief, then, that, even as Michelle seeks to bind her own story to that of her husband and, through him, to that of the nation, the story of her mother, Marian Robinson, hints at an exit. Robinson is a willfully marginal figure in the text, as she was in the White House—famously reluctant to move in, and evasive of its basic security protocols. She gave everything to her kids (“We were their investment,” Michelle writes of her parents’ devotion to their two children) and stood by her husband, Fraser Robinson III, while multiple sclerosis drained him of strength. And yet, it turns out, she harbored fantasies of leaving. It is here that Obama’s portrait of her mother grows most vivid: “Much later, my mother would tell me that every year when spring came and the air warmed up in Chicago, she entertained thoughts about leaving my father. I don’t know if these thoughts were actually serious or not. . . . But for her it was an active fantasy, something that felt healthy and maybe even energizing to ponder, almost as ritual.” Obama sees this ritual as an internal renewal of vows for Marian, akin to how doubts about God might be said to bolster one’s faith. But the fantasy also represents a wholly other possibility: not a knitting-together but an unfurling, a quiet dream of escape.