General Arlington History

Arlington was once part of Fairfax, the area that contains Arlington County was ceded to the new U.S. government by the Commonwealth of Virginia.

This is the general boundaries of Arlington County. The Potomac River is one of the side boundaries of Arlington also along the Potomac is the GW Memorial PKWY

Arlington County is surrounded by Fairfax County on the North West. Alexandria borders it to the south. It is located at 38°52′49″N 77°06′30″W / 38.88028°N 77.10833°W / 38.88028; -77.10833Coordinates: 38°52′49″N 77°06′30″W / 38.88028°N 77.10833°W / 38.88028; -77.10833.[26] It is adjacent along its southwest and southern borders to the cities of Falls Church and of Alexandria; and along the Potomac River north.[27] Included in the county are several neighborhoods, or "urban villages" such as Crystal City, Rosslyn, Ballston, Clarendon, Virginia Square, Westover, and Shirlington.

Durring the civil war, though Virginia was part of the confederacy it did not extent to northern Virginia or Arlington

Sources:

https://www.seabeehf.org/admin/wp-content/uploads/2011/02/ArlingtonDistMap.jpg

http://en.wikipedia.org/wiki/Arlington_County,_Virginia#Boundaries_and_jurisdictions

http://gsa.arlingtonva.us/search?q=arlington+boundaries&site=default_collection&output=xml_no_dtd&proxystylesheet=ACG_Site&client=ACG_Site&proxyreload=1