The Fortunes of MacKenzie Scott

But as Ms. Scott’s fame for giving away money has grown, so, too, has the deluge of appeals for gifts from strangers and old friends alike. That clamor may have driven Ms. Scott’s already discreet operation further underground, with recent philanthropic announcements akin to sudden lightning bolts for unsuspecting recipients.

Attempts to reach Ms. Scott and her husband, Dan Jewett, a chemistry teacher, for this article by phone, email and letter, directly and through intermediaries, were met with silence.

Instead, The New York Times relied on interviews with more than two dozen friends, teachers, former colleagues and acquaintances from every chapter of her life, as well as public records and the rare interviews Ms. Scott has given, generally in conjunction with the publication of one of her novels. This article is also based on previously unpublished letters between Ms. Scott and Ms. Morrison, kept in the Nobel laureate’s archive at the Princeton University library.

“I guess the only way I will find out what will not work for me in life is by trying it,” she wrote to Ms. Morrison in September 1992, a few months after graduation and at a pivotal moment for her future. Waitressing in New York had proved more grueling than waiting tables in Princeton during college, leaving her too tired to write.

“I found myself with unpredictable and small chunks of time during which I either collapsed from exhaustion and frustration, or ruminated over the excruciating monotony of making and selling sandwiches,” she wrote, “and worried about how I might pay my rent with the nickels they gave me in exchange for my ennui.”

The week before, she had started work at an investment firm, with her future husband, Mr. Bezos.

Three decades after worrying about making rent, and even in the wake of her recent gifts, Ms. Scott, 52, hovers around $50 billion, according to Forbes magazine. She has set about dispersing her enormous fortune with unprecedented speed and directness to frontline charities and nonprofits with a stated emphasis on advancing social justice and combating inequality, all while trying to keep herself out of the spotlight.

“Putting large donors at the center of stories on social progress is a distortion of their role,” she wrote in an essay last year, one in a series of deliberate public communiqués on her giving.