As Clarendon's profile both as a popular destination and marketing location have increased, its informal boundaries have expanded west toward Virginia Square and east toward Courthouse, two adjacent Metro station areas.

First platted in 1900 at the top of a hill on the Georgetown-Falls Church Road (now Wilson Boulevard), Clarendon evolved into Arlington County's original "downtown" after the arrival of electric trolleys in 1896.

Built in 1937, the Arlington Post Office is the first known federal building constructed in the county after the American Civil War that is not within a larger federally-owned property.

Many Vietnamese refugees immigrated to Washington D.C., and Arlington, due to the proximity to the nation's capital, and existing social, family, and business connections.

Business was attractive to Vietnamese immigrants in this neighborhood due to the depressed rents during the time of construction of the WMATA Clarendon metro station.

After the opening of the Clarendon Metro station in December 1979, luxury apartments, office buildings and upscale chain stores have been constructed and gentrified the area, although some of the original businesses remain.

[8] The largest annual event, "Clarendon Day,"[9] is held on a Saturday in mid-October and features four live music stages, local restaurant and coffee house booths, clothing, jewelry, antiques and collectibles sales, children's games and rides, an ice-cream eating contest and other local traditions.