Jimmy and Rosalynn Carter visit Georgia festival ahead of former president's 99th birthday, Carter Center says

Former President Jimmy Carter and his wife, Rosalynn, took a ride through the Plains Peanut Festival in Plains, Georgia, on Saturday, the Carter Center said in a social media post.

"Beautiful day for President & Mrs. Carter to enjoy a ride through the Plains Peanut Festival! And just a week before he turns 99. We're betting peanut butter ice cream is on the menu for lunch! #JimmyCarter99," the Carter Center said in a tweet sharing a video of the Carters riding in an SUV down a street lined with festival-goers.

Erikka Bettis Williams, who took the video, said she had no idea that the Carters would be there.

"Total surprise! The crowd was sort of slow to react at first because they didn't realize they were there. It was such a great surprise and yes, we sang 'Happy Birthday'!" she told CNN.

Jimmy Carter, who turns 99 on October 1, entered hospice care in February. The former president beat brain cancer in 2015 but faced a series of health scares in 2019, and consequentially underwent surgery to remove pressure on his brain.

In an interview with People published last month, the Carters' grandson said, "It's clear we're in the final chapter."

Family and caregivers had been the only recent visitors to the Carters' Plains home, Josh Carter told People.

Josh Carter said his grandmother Rosalynn Carter, who has dementia, is cognizant of her diagnosis. "She still knows who we are, for the most part - that we are family," he said.

Jimmy and Rosalynn Carter have been married for 77 years and are the longest-married presidential couple.

Jimmy Carter was born in Plains, Georgia, and grew up in the nearby community of Archery. A peanut farmer and Navy lieutenant before going into politics, the Democrat served one term as governor of Georgia and was president from 1977 to 1981.

CNN's Shania Shelton contributed to this story.