Virginia, officially the Commonwealth of Virginia, is a U.S. state located in the South Atlantic region of the United States. Virginia is nicknamed the "Old Dominion" and the "Mother of Presidents" after the eight U.S. presidents born there. The geography and climate of the Commonwealth are shaped by the Blue Ridge Mountains and the Chesapeake Bay, which provide habitat for much of its flora and fauna. The capital of the Commonwealth is Richmond; and Virginia Beach is the most populous city. Fairfax County is the most populous political subdivision. The wealthiest is Loudoun County. The Commonwealth's population is over eight million. The area's history begins with several indigenous groups, including the Powhatan. In 1607 the London Company established the Colony of Virginia as the first permanent New World English colony. Slave labor and the land acquired from displaced Native American tribes each played a significant role in the colony's early politics and plantation economy. Virginia was one of the 13 Colonies in the American Revolution and joined the Confederacy in the American Civil War, during which Richmond was made the Confederate capital and Virginia's northwestern counties separated to form the state of West Virginia. Although the Commonwealth was under conservative single-party rule for nearly a century following Reconstruction, both major national parties are competitive in modern Virginia. The Virginia General Assembly is the oldest legislature in the Western Hemisphere. The state government has been repeatedly ranked most effective by the Pew Center on the States. It is unique in how it treats cities and counties equally, manages local roads, and prohibits its governors from serving consecutive terms. Virginia's economy has many sectors: agriculture in the Shenandoah Valley; federal agencies in Northern Virginia, including the headquarters of the Department of Defense and CIA; and military facilities in Hampton Roads, the site of the region's main seaport. Virginia's public schools and many colleges and universities have contributed to growing media and technology sectors. As a result, computer chips have become the state's leading export.