Ms. Bottoms, who served as a choose and a metropolis councilwoman earlier than narrowly winning election to the mayor’s office in 2017, can be blessed with a voice — measured, compassionate, barely bruised and steeped in her expertise as a Black daughter and a Black mom — that appeared uniquely calibrated to deal with the challenges of the previous yr.

It was within the aftermath of the police killing of George Floyd in Minneapolis that Ms. Bottoms went on stay tv and have become a nationwide star as she spoke on to protesters. Some of their demonstrations had descended into lawlessness, with folks smashing home windows, spray-painting property and burning vehicles.

“Once I noticed the homicide of George Floyd, I harm like a mom would harm,” she stated. Then she scolded the protesters, insisting that they “go dwelling” and examine the precepts of nonviolence as practiced by the leaders of the civil rights motion.

Mr. Biden was one in all a number of nationwide figures to take discover. “We noticed her stand tall and converse out through the summer season of protests and ache,” the president stated on the March fund-raiser.

However the challenges had been quite a few.

On June 12, shortly after Mr. Floyd’s loss of life, a white Atlanta police officer fatally shot a Black man, Rayshard Brooks, in a fast-food restaurant’s parking zone. Extra protests and violence erupted, and the Bottoms administration fired the officer, Garrett Rolfe, a day after the capturing. (This week, the town’s Civil Service Board reinstated Officer Rolfe, who has been charged with murder, on the grounds that the administration had violated his due course of rights.)

Then, one month after the capturing, Ms. Bottoms tested positive for the coronavirus and was sued by Gov. Brian Kemp, a Republican, over a metropolis coverage requiring masks and mandating restrictions that had been stricter than these Mr. Kemp had set for the state.

In her letter on Thursday night time, Ms. Bottoms additionally famous that the Atlanta authorities had suffered a debilitating cyberattack shortly after she took workplace and was below the scrutiny of federal investigators who had begun a corruption investigation through the tenure of her predecessor, Kasim Reed.