At 10 A.M. on her last day of work, Vanita Gupta, the head of the Civil Rights Division at the Justice Department, opened a door in her office and stepped out into a conference room with cream-colored walls and a fireplace at one end. This room was once the office of the F.B.I. director J. Edgar Hoover, but now the Civil Rights Division uses it for meetings. That morning, Gupta and her senior leadership filed in. Before they took their seats, however, somebody noticed that the official portraits of President Obama and Attorney General Loretta Lynch had vanished. Now there was a bare spot on the wall; everyone stared at the two brass hooks. “When did the pictures come down?” Gupta asked.

The room went quiet, until finally a man from the facilities department, who was seated off to the side, spoke. “I just took them down,” he said, looking sheepish. “Sorry.”

In two days, Donald Trump would be sworn in as President, but as of that day Gupta was still the nation’s top civil-rights prosecutor. Nothing about her appearance fits the usual preconceptions of what somebody with her title might look like. She is only five feet two, and, while the lawyers who sat around the table were dressed in dark suits, she wore a candy-apple-red suit jacket and knee-high black boots. In 2014, she had been working as a deputy legal director at the A.C.L.U. when she got a call from the Attorney General’s office about the job. At the time, she was thirty-nine. “I was completely floored,” she recalled.

Gupta joined the Justice Department in the fall of 2014—nine weeks after Michael Brown was killed by a police officer in Ferguson, Missouri. She spent the next two years travelling all over the country—to Ferguson, Cleveland, New Orleans, Baltimore, and elsewhere—to meet with mayors, police chiefs, and citizens, in an attempt to repair the deeply damaged relationships between police departments and their communities. Under Obama, the Civil Rights Division took a more aggressive approach than ever before to stamping out systemic police abuse: the Division negotiated twenty-four agreements with law-enforcement agencies to reform their practices; fifteen of those agreements were consent decrees, which are enforced by a court.

On January 12th, Gupta had been in Baltimore announcing a consent decree with the Baltimore Police Department to address the egregious injustices identified by the Division in an earlier report. The next day, she had been in Chicago to release a devastating hundred-and-sixty-one-page report on that city’s police department. Now she had no idea what might come of all this work. Early in his tenure as Attorney General, Eric Holder had called the Civil Rights Division the “crown jewel” of the Justice Department. Now Senator Jeff Sessions—who had attacked the Civil Rights Division, in 2015, at a Senate hearing called “The War on Police,” saying that it had “an agenda that’s been a troubling issue for a number of years”—was poised to become the next Attorney General.

During the Obama Presidency, the Civil Rights Division was at the center of many of the nation’s most contentious political battles: over policing as well as voting rights, fair housing, hate crimes, and transgender rights. Twice a week, Gupta held meetings in the conference room with her senior staff, with each person giving an update on his or her work—on an ongoing investigation, or a case that was about to be filed. But on her final day the first order of business was a conference call with the entire staff. “Good morning, everyone,” Gupta said. “Today is my last day here at the Civil Rights Division, and I just wanted to say a few words.” Most of the fifteen people seated around the table were political appointees, who would leave their jobs by the end of the week. But the Civil Rights Division has some seven hundred employees, including three hundred and eighty-three attorneys, and all of those not in the room would be staying—at least for now.

Gupta gave a passionate speech about the importance of their jobs. (“I think our work has been simply transformative at a time when civil rights was front and center in the country,” she said.) She thanked everyone for their hard work, then concluded, “When I came in, I was asked by my bosses to push hard, and to make the most out of the time that I had. And I feel like we have not wasted a minute. But my ask of you today is that I need you to keep pushing. Even when it’s hard, I need every single one of you to keep pushing, because there are too many people in this country who are depending on us.”

Her voice began to waver, and tears collected in her eyes. “I’m sorry. I was trying to get through this without crying,” she said. “But you are the heart and soul of the Civil Rights Division, and I am counting on you—as are people all over the country—for the tireless work and your undying commitment to justice and equality and fairness for all.” She added, “Good luck, keep the faith, and keep fighting.” After the call ended, the lawyers and other staff around the table broke into applause. Gupta lifted a tissue to wipe away her tears. “I don’t think you have to apologize for that,” one lawyer said. By now, a few other lawyers were dabbing at their eyes, too.

Toward the end of the day, Gupta returned to her office. She had worked late the night before trying to clear it out, but she still had a ways to go. A photograph of Holder hung on one wall, his arm slung around her, her head reaching only to his shoulder. (“I expect great things from you,” he wrote beneath the picture.) On the coffee table in front of her desk, there were piles of books with titles like “Race, Riots, and the Police” and “Stop and Frisk: The Use and Abuse of a Controversial Policing Tactic.” Gupta does not have a job lined up, but she sounded untroubled when she talked about her own future. When she spoke about the future of the Civil Rights Division, however, she became emotional. “It’s hard,” she said. “It’s just hard to know who we’re handing everything to.” Outside her window, on Pennsylvania Avenue, she could see metal bleacher stands set up for Trump’s Inauguration parade.

That day, Gupta’s plan was to leave the office by 5 P.M. and join her colleagues at a local bar. But five o’clock came, and Gupta did not leave. She sat at her desk, typing e-mails, while two young employees—her speechwriter and a press secretary—helped pack up her office: taping bubble wrap around glass awards, putting books in boxes, carting everything to her car. At five-forty, she was still there, working. The sky outside her window began to darken. One of her co-workers kept calling from the bar, telling her to hurry up, everyone was waiting for her.

She pulled out a stack of newspapers from beneath her desk, including three issues of the Times from last August, when the Civil Rights Division’s work in Baltimore had made the front page three days in a row. She stuffed the newspapers in a tote bag, and threw in a couple of pairs of high heels. Finally, at five-fifty-five, she turned off her office lights and walked out, with the two young staffers. She debated asking one of them to take a picture of her leaving the Department of Justice, then decided not to bother; she didn’t really want to remember this moment. They got into the elevator, and, as the doors drew shut, she said, “Goodbye, D.O.J.”