The General Store, which dates from the turn-of-the-last-century, was originally located just west of the old Platts' Drugstore in Port Sanilac. When the Platts family decided to add a parking area to the property, Charlie Platts and his sister, Ruth Platts Glencer, donated the clapboard building to the museum. The structure had been used as a bank, a feed store, a barbershop, and a storage facility over the years. It was moved to the museum grounds in the late 1980's.
Today, the General Store is half exhibit and half gift shop. The building holds, among other things, antique merchandise items found in the cupboards of the house, a classic cash register, a gigantic coffee grinder, and the original post office box unit from the Argyle Post Office. Old fashioned toys, vintage candy and local history books are among those items for sale.