As of the census of 2000, there were 85,951 people, 31,223 households, and 23,292 families residing in the county. The population density was 247 people per square mile (95/km²). There were 34,461 housing units at an average density of 99 per square mile (38/km²). The racial makeup of the county was 93.39% White, 3.91% Black or African American, 0.33% Native American, 0.69% Asian, 0.03% Pacific Islander, 0.50% from other races, and 1.15% from two or more races. 1.52% of the population were Hispanic or Latino of any race. 17.9% were of German, 16.1% Irish, 13.8% English, 13.8% American and 6.5% Italian ancestry according to Census 2000.
There were 31,223 households out of which 37.00% had children under the age of 18 living with them, 58.60% were married couples living together, 11.10% had a female householder with no husband present, and 25.40% were non-families. 19.90% of all households were made up of individuals and 7.10% had someone living alone who was 65 years of age or older. The average household size was 2.71 and the average family size was 3.12.
In the county the population was spread out with 27.70% under the age of 18, 7.50% from 18 to 24, 31.20% from 25 to 44, 23.20% from 45 to 64, and 10.50% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 98.20 males. For every 100 females age 18 and over, there were 95.70 males.
The median income for a household in the county was $50,510, and the median income for a family was $56,469. Males had a median income of $40,350 versus $28,646 for females. The per capita income for the county was $21,384. About 5.40% of families and 7.20% of the population were below the poverty line, including 9.20% of those under age 18 and 7.70% of those age 65 or over.
May 2008 the county commissioners adopted a 10% property tax increase. This is in addition to the property tax increase added by the increasing property assessments, which are increased each year and reassessed every 3 years.
Maryland state planning data suggest that the population of the county could double in the next thirty years, reaching 160,000 by 2030.