The only known copy of a 1913 silent film about US President Abraham Lincoln was found in a barn clear-out.
A contractor cleaning out the old New Hampshire barn which was destined for demolition in 2006 found seven reels of nitrate film inside, including When Lincoln Paid.
The 30-minute film is about the mother of a dead Union soldier asking Lincoln to pardon a Confederate soldier whom she had initially turned in.
It starred Francis Ford, the brother of John Ford, the director of The Grapes of Wrath, The Quiet Man, and other classics.
"I was up in the attic space, and shoved away over in a corner was the film and a silent movie projector, as well," movie buff Peter Massie said of his discovery in the western New Hampshire town of Nelson. "I thought it was really cool."
The film canisters sat in Mr Massie's basement for a while before he thought of contacting nearby Keene State College, where film professor Larry Benaquist thought it was a rare find.
After working with the George Eastman House film preservation museum in Rochester, New York, the college determined that the film did not exist in film archives. In fact, it was one of eight silent films starring Ford as Lincoln - there are no known surviving copies of the others.
"The vast majority of silent films, particularly from the early period - the first decade of the 20th century - are gone," said Caroline Frick Page, curator of motion pictures at George Eastman House.
"That's what makes these stories so incredibly special."
The college, which plans a film screening next week, received a grant from the National Film Preservation Foundation to restore it. It took a Colorado laboratory a year to complete the task.
Prof. Benaquist said the images themselves were well preserved, probably because they endured decades of New England winters in the barn, which also was well sheltered by trees.
Nitrate film, which was phased out in Hollywood in the 1950s, is highly flammable. The 35mm film itself had shrunk and the sprocket holes used on projectors were shredded.
"What the laboratory had to do was remanufacture the sprocket holes to a new dimension, make it in strips, adhere it to the image, and then run it through a printing process where they would print it, frame by frame," Prof. Benaquist said.
Prof. Benaquist thinks the film was discovered in Nelson because the town is on Granite Lake, the site of many summer camps through the years. He said there was a boys' camp in the area of the barn and believes the films were shown to entertain the children, then put away and forgotten.