The carved-back, cane-seat parlor chair from the presidential box was donated to the U.S. government by an anonymous Virginia family last week, the Washington Post reported Monday.
"This is a fabulous thing we've been given. We're very excited about it," Gloria Swift, the National Park Service's curator for Ford's Theatre, told the newspaper.
The chair apparently made its way out of the building via a construction worker on the crew charged with turning the theater into an office building after John Wilkes Booth assassinated the president.
The worker gave the parlor chair to the Virginia family, where it was handed down for generations, Swift said.
The space was restored in the 1950s with replicas of the chairs on which Lincoln and his wife were sitting that night. Lincoln's chair is in the Henry Ford Museum in Dearbon, Mich.