Carter wore an Atlanta Braves baseball cap, but his left eye was swollen and bruised and he had a white bandage above his eye.
Deanna Congileo said in an e-mail that the 39th president fell Sunday in Plains and received stitches.
The Carters were introduced by country stars Garth Brooks and Trisha Yearwood, who called the Carters the hardest working volunteers, and sang some duets during the concert and ceremony.
For his 95th birthday, the former commander-in-chief, who has been nicknamed the "active ex-president", took the day off to relax by celebrating with a "quiet day at home", according to a spokeswoman. "My cap? The Braves just beat the Cardinals 3 to 1", said Carter, who is the oldest living former USA president.More news: Month After Dorian, Dog Rescued From Underneath Rubble
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The 95-year-old former president required stitches above his eyebrow, Carter's non-profit organisation said in a statement on Twitter on Sunday.
Over the weekend, Carter and his wife, former first lady Rosalynn, traveled to Nashville, where they led the way on a new Habitat for Humanity home build set to be completed by the end of the week.
The title of oldest living former us president was held by the late George H.W. Bush, who died in late 2018 at 94. Once seated, Carter, who still teaches Sunday school twice a month at Maranatha Baptist Church in Plains, Georgia, spoke in a clear voice, peppering his inspirational message with jokes.
Carter has also overcome serious health issues, including brain and liver cancer in 2015.
Carter also has been accepting visits from several 2020 presidential candidates of late, but he's held back on endorsing any of his fellow Democrats, offering few clues about his thoughts of the campaign.