Arlington County, or simply Arlington, is a county in the U.S. state of Virginia. The county, which is located in the Washington metropolitan area and the broader Northern Virginia region, is positioned directly across from Washington, D.C., the national capital, on the southwestern bank of the Potomac River. The smallest self-governing county in the United States by area, Arlington County has both suburban and urbanized districts. Its urbanized districts are located in proximity to several Washington Metro stations and lines. Its seat of government is located in the Court House neighborhood, which hosts many of its administrative offices and county courthouse.
Originally part of the Nacotchtank tribe's territory prior to the establishment of the Colony of Virginia in 1606, English colonists began settling in Arlington by the 1670s; the area was eventually designated as part of Fairfax County in 1742. The colonial-era economy was mostly based in tobacco agriculture operated with enslaved labor and indentured servants on large plantations. Following the end of the Revolutionary War, Arlington's planters and yeoman farmers transitioned to other crops. Virginia ceded present-day Arlington to help form the District of Columbia, and from 1801 the area was known as Alexandria County; it was eventually retroceded back to Virginia in 1847 as a result of pressure from Alexandria, which was the county's primary commercial center.