the west by Sideling Hill Creek and Allegany County, Maryland, and to the east by Frederick County and South Mountain. Adjacent counties Fulton County, Pennsylvania (northwest) Allegany County (west) Morgan County, West Virginia (southwest) Berkeley County, West Virginia (south) Jefferson County, West Virginia (south) Loudoun County, Virginia (southeast) Frederick County (east) Franklin County, Pennsylvania (northeast) Major highways Interstate 68 Interstate 70 Interstate 81 U.S. Route 11 U.S. Route 40 U.S. Route 40 Alternate U.S. Route 340 U.S. Route 522 Maryland Route 34 Maryland Route 56 Maryland Route 57 Maryland Route 58 Maryland Route 60 Maryland Route 62 Maryland Route 63 Maryland Route 64 Maryland Route 65 Maryland Route 66 Maryland Route 67 Maryland Route 68 Maryland Route 77 Maryland Route 144 Maryland Route 180 Maryland Route 418 Maryland Route 491 Maryland Route 494 Maryland Route 550 Maryland Route 615 Maryland Route 632 Demographics 2000 census As of the census of 2010, there were 147,430 people, 49,726 households, and 34,112 families residing in the county. The population density was . There were 52,972 housing units at an average density of 116 per square mile (45/km2). The racial makeup of the county was 89.71% White or Caucasian, 7.77% Black or African American, 0.18% Native American, 0.80% Asian, 0.04% Pacific Islander, 0.46% from other races, and 1.04% from two or more races. 1.19% of the population were Hispanic or Latino of any race, 32.1% identified as being of German ancestry, 21.4% American, 8.8% Irish, and 8.4% English ancestry. There were 49,726 households, out of which 31.30% had children under the age of 18 living with them, 54.00% were married couples living together, 10.70% had a female householder with no husband present, and 31.40% were non-families. 26.00% of all households were made up of individuals, and 11.10% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.96. In the county, the population was spread out, with 23.40% under the age of 18, 8.10% from 18 to 24, 31.30% from 25 to 44, 23.00% from 45 to 64, and 14.20% who were 65 years of age or older. The median age was 37 years. For every 100 females, there were 104.50 males. For every 100 females age 18 and over, there were 104.00 males. 2010 census As of the 2010 United States Census, there were 147,430 people, 55,687 households, and