This complex of structures in the Cromwell’s Run Rural Historic District reflects an early gristmill operation and the area’s 20th-century hunt-country society. A mill was operated here by Charles Chinn as early as 1768. Leven Powell, founder of Middleburg, was responsible for many of the present buildings, including, the present mill, the miller’s house, the cooper’s house, a dairy-smokehouse, and the mill owner’s house (now the centerpiece of the complex). After the mill ceased operation, the Fauquier County property took on an entirely new aspect with ts purchase by John S. Phipps, son of Henry Phipps, a partner of Andrew Carnegie and founder of the United States Steel Corporation. From 1924 to 1929 Phipps enlarged the house, converted several outbuildings to guest quarters, added a stable and swimming pool, and united the complex with landscaping. Though today a splendid country estate, the rustic character of Chinn’s Mill House has been maintained.