Outdoor Advertising Billboards for Rent in Loudoun County, Virginia

Loudoun County (pronounced /ˈlaʊdən/ "LOUD-un") is a county located in the Commonwealth of Virginia, and is part of the Washington Metropolitan Area. As of July 2006, the county is estimated to be home to 268,817 people, a 58 percent increase over the 2000 figure of 169,599. That increase makes the county the fastest growing in the United States during that period. Its county seat is Leesburg. As of 2007, the town had been county seat for 249 of the last 250 years.

As of 2007, Loudoun County has the highest median household income in the United States at $107,207, beating neighboring Fairfax County at $105,241. The two counties have been trading places as the wealthiest county in the US for the past couple of years.

Demographics

Historical populations
Census	Pop.		%±
1900	21,948		—
1910	21,167		−3.6%
1920	20,577		−2.8%
1930	19,852		−3.5%
1940	20,291		2.2%
1950	21,147		4.2%
1960	24,549		16.1%
1970	37,150		51.3%
1980	57,427		54.6%
1990	86,129		50.0%
2000	169,599		96.9%
Est. 2007	278,797		64.4%

As of the census of 2000, there were 169,599 people, 59,900 households, and 45,044 families residing in the county. The population density was 326 people per square mile (126/km²). There were 62,160 housing units at an average density of 120 per square mile (46/km²). The racial makeup of the county was 82.79% White, 6.89% Black or African American, 5.35% Asian, 0.21% Native American, 0.06% Pacific Islander, 2.26% from other races, and 2.44% from two or more races. 5.95% of the population were Hispanic or Latino of any race. 15.0% were of German, 11.8% Irish, 10.9% English, 9.0% American and 6.6% Italian ancestry according to Census 2000.

According to the 2006 American Community Survey 72.0% of Loudoun County's population was white; 7.6% of the population was African-American. 0.1% were Native Americans; Asians were 13.1%. 4.9% of the population was of some other race and 2.3% of people reported being of two or more races. Latinos of any race were 9.7% of the population. 21.0% of the population was foreign born, up from 11.27% in 2000 and 5.67% in 1990.

As of 2000 there were 59,900 households out of which 43.10% had children under the age of 18 living with them, 64.30% were married couples living together, 7.80% had a female householder with no husband present, and 24.80% were non-families. 18.40% of all households were made up of individuals and 3.70% had someone living alone who was 65 years of age or older. The average household size was 2.82 and the average family size was 3.24.

In the county, the population was spread out with 29.80% under the age of 18, 5.70% from 18 to 24, 38.90% from 25 to 44, 20.00% from 45 to 64, and 5.60% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 97.80 males. For every 100 females age 18 and over, there were 95.50 males.

In August 2008, Census survey data concluded that Loudoun County has the highest median income in the country at just over $107,000. A 2007 estimate indicated that the median income for a household was $104,612, and the median income for a family was $125,381