The Gen. William Mitchell House, also known as Boxwood or the Gen. Billy Mitchell House was the country estate and home of General Billy Mitchell (1879-1936) during the last ten years of his life, from 1926 through 1936. Mitchell was an American general who is regarded as the father of the U.S. Air Force. He is regarded as one of the most famous and most controversial figures in American airpower history. The house was declared a National Historic Landmark in 1976. It is located about .5 mile south of Middleburg on Virginia Route 626, straddling the county lines of Fauquier and Loudoun Counties. Part of the estate is now home to Boxwood Estate Winery.