The tintype photograph was in a bin, about to be shipped out, when a worker grabbed it and sent it to the charity's local online department. The item was then put up for auction, which closed Wednesday night.
"It would have gone to our outlet store where everything is sold by the pound," Goodwill spokeswoman Suzanne Kay-Pittman said Thursday. She estimated the tintype would have fetched a dollar and change based on its weight.
The sale was a record for the charity. The previous record was an early 1900s watercolor that sold for $7,500 in 2009 to a museum in New Orleans, The Tennessean reported.
The newspaper first reported the photograph sale.
Kay-Pittman said Thursday that the successful bidder lives in Virginia but officials didn't immediately know his name.
"We're doing a happy dance," she said. "We're beyond thrilled."