Walnut Grove The McCormick Farm, located at the Shenandoah Valley Agricultural Research and Extension Center operated by Virginia Tech. McCormick Homestead Walnut Grove plaque   Schoolhouse and Housekeeper's quarters a second view of the house   Site of the ice house behind the hoouse Carriage house The house can be seen up on the hill from the mill and blacksmith shop. Above is the plaque given to Cyrus McCormick, marking Walnut Grove as a National Landmark--the location where the mechanical reaper was invented. The top of the Blacksmith Shop has been converted into a museum (left) which houses a model of a mechanical reaper (right). The Blacksmith Shop (upper left) displays old farm equipment, smithing tools (lower left) and the fire hearth (right) which the McCormicks used to weld and fashion their equipment. Grist Mill   The mill was used to grind grain for the farm and is open to view the large cog wheels (right) at work.   Blacksmith Shop and Grist Mill