Carroll County is a county located in the U.S. state of Maryland. As of the 2010 census, the population was 167,134. Its county seat is Westminster.
According to the U.S. Census Bureau, the county has a total area of 453 square miles (1,170 km), of which 448 square miles (1,160 km) is land and 5.1 square miles (13 km) (1.1%) is water.
Topographically, Carroll County is located within the Piedmont Plateau region, with characteristic upland terrain of rolling hills and deciduous forest. The most prominent relief is Parr’s Ridge, which bisects the county from southwest to northeast. The highest point is in the northeastern part of the county on Dug Hill along Deep Run Road.
Carroll County is bordered on the north by the Mason–Dixon line with Pennsylvania, and on the south by Howard County across the South Branch of the Patapsco River. About half of the eastern border, with Baltimore County, is formed by the North Branch of the Patapsco River and by Liberty Reservoir, though the northern half near Manchester and Hampstead is a land border. Carroll County is bordered on the west by Frederick County, across the Monocacy River and Sam’s Creek. Other major streams in the county include Big Pipe Creek, Little Pipe Creek, and Double Pipe Creek, Bear Branch, and the headwaters of the Gunpowder Falls. The Piney Run Reservoir is in the southern part of the county.
Three railroad lines cross Carroll County. The old Baltimore and Ohio (B&O) Old Main Line crosses the southern part of the county from east to west, with former stations in Sykesville and Mount Airy. The original Western Maryland Railway (WM) main line track runs southeast to northwest through Carrollton, Westminster, New Windsor, and Union Bridge. The old Baltimore and Hanover Railroad (later acquired by WM) runs further to the east through Hampstead, Millers, and Lineboro. Two of these railroad lines are now operated by CSX Transportation; the former WM main line is now operated by Maryland Midland Railway.
As of the census of 2000, there were 150,897 people, 52,503 households, and 41,109 families residing in the county. The population density was 336 people per square mile (130/km²). There were 54,260 housing units at an average density of 121 per square mile (47/km²). The racial makeup of the county was 95.69% White, 2.28% Black or African American, 0.22% Native American, 0.75% Asian, 0.02% Pacific Islander, 0.31% from other races, and 0.73% from two or more races. 0.99% of the population were Hispanic or Latino of any race. 30.5% were of German, 14.0% Irish, 11.1% United States or American, 10.7% English and 7.3% Italian ancestry.
There were 52,503 households out of which 39.70% had children under the age of 18 living with them, 66.50% were married couples living together, 8.30% had a female householder with no husband present, and 21.70% were non-families. 17.50% of all households were made up of individuals and 7.40% had someone living alone who was 65 years of age or older. The average household size was 2.81 and the average family size was 3.18.
In the county, the population was spread out with 27.70% under the age of 18, 7.00% from 18 to 24, 30.60% from 25 to 44, 23.90% from 45 to 64, and 10.80% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 97.40 males. For every 100 females age 18 and over, there were 94.00 males.
The median income for a household in the county was $60,021, and the median income for a family was $66,430 (these figures had risen to $78,912 and $90,376 respectively as of a 2007 estimate). Males had a median income of $44,191 versus $30,599 for females. The per capita income for the county was $23,829. About 2.70% of families and 3.80% of the population were below the poverty line, including 4.00% of those under age 18 and 4.90% of those age 65 or over.
As of 2007, Carroll County was the tenth wealthiest county in the country in its population range of 65,000 to 250,000
As of the 2010 census the population was 167,134. The racial makeup was 91.20% Non-Hispanic whites, 3.19% blacks, 0.20% Native Americans, 1.45% Asians, 0.03% Pacific Islanders, 0.09% Non-Hispanics of some other race, 1.33% Non-Hispanics reporting two or more races and 2.61% Hispanics.
As of the 2010 United States Census, there were 167,134 people, 59,786 households, and 45,163 families residing in the county. The population density was 373.4 inhabitants per square mile (144.2/km). There were 62,406 housing units at an average density of 139.4 per square mile (53.8/km). The racial makeup of the county was 92.9% white, 3.2% black or African American, 1.4% Asian, 0.2% American Indian, 0.7% from other races, and 1.5% from two or more races. Those of Hispanic or Latino origin made up 2.6% of the population. In terms of ancestry, 33.8% were German, 19.1% were Irish, 14.0% were English, 8.4% were American, 8.2% were Italian, 5.3% were Polish, 2.8% were French and 2.3% were Scottish.
Of the 59,786 households, 37.2% had children under the age of 18 living with them, 62.8% were married couples living together, 8.6% had a female householder with no husband present, 24.5% were non-families, and 20.0% of all households were made up of individuals. The average household size was 2.74 and the average family size was 3.15. The median age was 41.1 years.
The median income for a household in the county was $81,621 and the median income for a family was $95,825. Males had a median income of $62,322 versus $46,170 for females. The per capita income for the county was $33,938. About 4.0% of families and 5.3% of the population were below the poverty line, including 6.6% of those under age 18 and 6.0% of those age 65 or over.