Throughout the past several weeks, as protests over the killing of George Floyd rippled through America’s cities, a 79-year-old retired schoolteacher has spent her days watching the news in her home in Albany, Ga., sometimes with tears running down her face.

For Rutha Mae Harris, who once marched and was jailed with the Rev. Dr. Martin Luther King Jr., it is like revisiting her past.

There have been times when she wondered what her generation had achieved. But the past weeks — particularly the sight of kneeling police officers and throngs of white faces — have offered some redemption.

“I love it, I love it, I love it,” she said. “It has surprised me, and it gives me hope. I thought what I had done was in vain.”

For the dwindling cadre of civil rights activists like Ms. Harris who took to the streets 60 years ago, this is a moment of trepidation and wonder.

Their activism gave the world images — the snarling police dogs of Birmingham, Ala., the beatings of Selma, Ala. — that changed the trajectory of race in America. Now they are watching another movement unfold, familiar but utterly changed.

Dr. King surrounded himself with a variety of thinkers, and in recent weeks, his allies took different views of the Floyd protests.

But they all marveled at their quicksilver spread. In their time, major actions were the result of months of planning, punctuated by all-night arguments over strategy and phone-tree lobbying to get reporters to show up. Five years passed between Emmett Till’s lynching and the Greensboro, N.C., sit-ins. Another year passed between the sit-ins and the Freedom Rides.

“A movement is different from a demonstration,” said Taylor Branch, a historian of the civil rights era.

“It’s not automatic — it’s the opposite of automatic,” he said, “that a demonstration in the street is going to lead to a movement that engages enough people, and has a clear enough goal that it has a chance to become institutionalized, like the Voting Rights Act.”

Dr. King’s confidant Bernard Lafayette, 79, could not contain his excitement about recent demonstrations; he has been offering advice to young activists from his home in Tuskegee, Ala. Andrew Young, 88, a former mayor of Atlanta, has vented his frustration over looting and vandalism. And Bob Moses, 85, was cautious in his comments, saying the country seemed to be undergoing an “awakening.”

“I think that’s been its main impact, a kind of revelation about something that has been going on for over a century, a century and a half, right under your noses,” Mr. Moses said. “But there isn’t any indication of how to fix it.”