The 1810 New England "Yankee Barn" was moved to the Portage County Historical Society in 1974. It had been located on Dawley Road in Ravenna Township. Miss Ardis Pfile was the donor of the barn. It had been in her family for nearly 120 years. The Dawley family owned the land earlier.

Dr. Alfred C. Mahan, a former Portage County resident, living in Willoughby, Ohio at the time, provided generous funding for the moving and rebuilding of the barn. It is named in honor of his mother and father.

According to past Portage County Historical Society newsletters:
Amish men from Burton, Ohio disassembled the barn in February 1974. As the barn was being taken apart they marked each piece for the proper reconstruction on the museum grounds. It took three days to move all the pieces from the Pfile property to the museum grounds. Amish men Robert Detwiler and his brothers Lester, Owen and Minno and a cousin Christ Byler along with Cy Plough and Ed Ruester laid the foundation stones and sub-plate for the framework of the barn. Some of the posts from the barn were decayed and needed to be replaced. A barn built in 1830 in Palmyra Township, originally owned by the Hughes family, located on Whippoorwill Road, was being torn down by current owner William Francis. Material from the barn was donated to help finish the Mahan Barn. According to the Society's newsletters on November 1, 1974 the frame of the barn was completed as of June 3, 1975 the siding was completed, the floor was being laid and the doors were ready to hang. In November 1975 the wood shingles had been purchased and work progressed on the roof as weather allowed. The Barn was finished in August 1976. The barn measures 40 feet x 30 feet.
Also assisting in the project were: Gene Morris, William Nash, Ed Ruester, Joe Waranai, Earl Proehl, Herman Miller Jr., Jim Justice, Dave Simon, Fred Laughlin, Ralph Gates, Bob Fleishman, and Robert Seton.

A shed roof addition has been added on the west and south side of the barn.This area contains larger farm implements and wagons that have recently been donated to the museum.

The barn is currently used for storage of wagons and other farm tools and is open for viewing during regular hours if volunteer is available.