Alexandria is an independent city in the United States Commonwealth of Virginia. As of the 2010 census, the population was 139,966, and in 2015, the population was estimated to be 153,511. Located along the western bank of the Potomac River, Alexandria is approximately 7 miles (11 km) south of downtown Washington, D.C.Like the rest of Northern Virginia, as well as Central Maryland, modern Alexandria has been influenced by its proximity to the U.S. capital. It is largely populated by professionals working in the federal civil service, in the U.S. military, or for one of the many private companies which contract to provide services to the federal government. One of Alexandria's largest employers is the U.S. Department of Defense. Another is the Institute for Defense Analyses. In 2005, the United States Patent and Trademark Office moved to Alexandria.The historic center of Alexandria is known as "Old Town". With its concentration of boutiques, restaurants, antique shops and theaters, it is a major draw for all who live in Alexandria as well for visitors. Like Old Town, many Alexandria neighborhoods are compact and walkable. It is the 7th largest and highest-income independent city in Virginia.A large portion of adjacent Fairfax County mostly south, but also west of the city is named "Alexandria," but it is under the jurisdiction of Fairfax County and separate from the city; the city is sometimes referred to as the City of Alexandria to avoid confusion (see the "Neighborhoods" paragraph below). In 1920, Virginia's General Assembly voted to incorporate what had been Alexandria County as Arlington County to minimize confusion.