Anne Arundel County (/əˈrʌndəl/), also notated as AA or A.A. County, is a county located in the U.S. state of Maryland. As of the 2010 United States Census, its population was 537,656, a population increase of just under 10% since 2000. Its county seat is Annapolis, which is also the capital of the state. The county is named for Lady Anne Arundell (1615–1649), a member of the ancient family of Arundells in Cornwall, England, and the wife of Cecilius Calvert, 2nd Baron Baltimore (1605–1675), founder and first Lord Proprietor of the colony Province of Maryland.
According to the U.S. Census Bureau, the county has a total area of 588 square miles (1,520 km), of which 415 square miles (1,070 km) is land and 173 square miles (450 km) (29%) is water. Anne Arundel County is located to the south of the city of Baltimore.
Most of the county’s borders are defined by water. To the east lies the western shore of the Chesapeake Bay, and numerous tidal tributaries of the Bay indent the shoreline, the various rivers, creeks, streams, inlets forming prominent peninsulas, also known as “necks” (as further south in Virginia). The largest of these tributaries include (from north to south), the Magothy River, Severn River, South River, and the West River. Further south, the upper Patuxent River forms the border of Anne Arundel with Prince George’s County to the west. Deep Run forms part of the northwestern border with Howard County, and Lyons Creek forms part of the southern border with Calvert County. The Patapsco River to the north is the border with Baltimore County, but the communities and areas of Brooklyn and Curtis Bay neighborhoods (and adjacent Fairfield, Wagner’s Point [also known as East Brooklyn], Arundel Cove [off of Curtis Creek], and Hawkins Point), lying south of the Patapsco River were annexed from Anne Arundel County to Baltimore City in the third major annexation of January 1919.
Anne Arundel County originally included all of the land between the Patuxent River and the Patapsco River (mainstem and South Branch) upstream to their headwaters on Parr’s Ridge. The northwestern section of this long tract later became Howard County, with the border between the two running very close to the Atlantic Seaboard fall line. As a result, Anne Arundel County lies almost entirely within the Atlantic Coastal Plain while Howard County is almost entirely within the Piedmont province.
Elevations in Anne Arundel County range from sea level at the Chesapeake and tidal tributaries to approximately 300 feet (91 m) in western areas near the fall line. The terrain is mostly flat or gently rolling, but more dramatic banks and bluffs can be found where waterways cut through areas of higher elevation.
With the exception of the very limited extent of Piedmont underlain by Precambrian to early Paleozoic metamorphic rock, all of the county is underlain by thick deposits of gravel, sand, silt, and clay dating from the early Cretaceous to Holocene times. Most of these sediments are unconsolidated but include local formations of sandstone, especially in the Pasadena area.
As of the 2010 United States Census, there were 537,656 people, 199,378 households, and 139,262 families residing in the county. The population density was 1,295.9 inhabitants per square mile (500.3/km). There were 212,562 housing units at an average density of 512.3 per square mile (197.8/km). The racial makeup of the county was 75.4% White, 15.5% Black or African American, 3.4% Asian, 0.3% American Indian, 0.1% Pacific Islander, 2.4% from some other race, and 2.9% from two or more races. Those of Hispanic or Latino origin made up 6.1% of the population. In terms of ancestry, 23.3% were German, 18.6% were Irish, 12.3% were English, 7.4% were Italian, 5.0% were Polish, and 4.4% were American.
Of the 199,378 households, 34.6% had children under the age of 18 living with them, 53.1% were married couples living together, 12.1% had a female householder with no husband present, 30.2% were non-families, and 23.7% of all households were made up of individuals. The average household size was 2.63 and the average family size was 3.11. The median age was 38.4 years.
The median income for a household in the county was $83,456 and the median income for a family was $97,557. Males had a median income of $63,187 versus $48,750 for females. The per capita income for the county was $38,660. About 3.3% of families and 5.3% of the population were below the poverty line, including 6.9% of those under age 18 and 5.5% of those age 65 or over.
As of the census of 2000, there were 489,656 people, 178,670 households, and 129,178 families residing in the county. The population density was 1,177 people per square mile (455/km²). There were 186,937 housing units at an average density of 449 per square mile (174/km²). The racial makeup of the county was 81.24% White, 13.57% Black or African American, 0.30% Native American, 2.29% Asian, 0.06% Pacific Islander, 0.85% from other races, and 1.69% from two or more races. 2.63% of the population were Hispanic or Latino of any race. 17.7% were of German, 13.1% Irish, 10.5% English, 8.1% United States or American and 7.0% Italian ancestry.
There were 178,670 households out of which 34.90% had children under the age of 18 living with them, 57.20% were married couples living together, 11.10% had a female householder with no husband present, and 27.70% were non-families. 21.30% of all households were made up of individuals and 6.40% had someone living alone who was 65 years of age or older. The average household size was 2.65 and the average family size was 3.09.
In the county, the population was spread out with 25.20% under the age of 18, 8.10% from 18 to 24, 32.80% from 25 to 44, 23.90% from 45 to 64, and 10.00% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 99.10 males. For every 100 females age 18 and over, there were 97.10 males.
As of Census 2010 the population was 537,658. The ethnic and racial make-up of the county population was 72.42% Non-Hispanic white, 15.52% black, 0.31% Native American, 3.41% Asian, 0.16% Non-Hispanic of some other race, 2.37% non-Hispanics of two or more races and 6.12% Hispanic.