The Loudoun Valley is a small, but historically significant valley in the Blue Ridge Mountains located in Loudoun County in Northern Virginia in the United States. Geography The lush and fertile valley lies between Catoctin Mountain and the Bull Run Mountains to the east and the Blue Ridge Mountains to the west. To the north it is bound by the Potomac River and to the south by the Broken Hills of Fauquier County. The small portion of the valley residing in Fauquier County is known as Upper Fauquier. The valley varies between and in width and is approximately long. The northern section of the valley is bisected by Short Hill Mountain. The area west of the Short Hill is known as Between the Hills and is distinct from the Loudoun Valley, while the area to the east, sometimes referred to as the Catoctin Valley, is associated with it. Major watercourses include Goose Creek, Catoctin Creek, Panther Skin Run, and the Little River. The three major highways across the valley are U.S. Route 50, which runs from Aldie on the east to Ashby Gap on the west; Route 7, which runs from Clarke's Gap west of Leesburg to Snickers Gap west of Bluemont; and Route 9, which diverges from Route 7 at Clarke's Gap and runs west to Keyes Gap on the West Virginia border. The terrain is rolling, with numerous ridges and hills; the elevation here ranges between above sea level. The soil is formed from gneiss, clay / slate, hornblende, greenstone, and quartz particles, a fertile and durable soil, containing alumina, silex, potash, lime, and other natural fertilizing minerals. History Settlement Following the 1722 Treaty of Albany, which expelled Indigenous nations west of the Blue Ridge Mountains, white settlers began to occupy the Loudoun Valley. Many of the early white residents were immigrants from southern Pennsylvania — Quakers, Scotch-Irish, and Germans interested in starting small farms. The Quakers had significant influence in the central Loudoun Valley, settling in and around such communities as Waterford, Hillsboro, Goose Creek (now Lincoln), and Union (now Unison). Their stone buildings are a major feature of the Loudoun landscape. Germans settled in the northern end of the Loudoun Valley, especially in the area around Lovettsville, leaving a number of log structures as their architectural legacy. Unlike the settlers to the east and south, neither of these groups practiced slavery. In the southern portion of