As of the census of 2000, there were 79,894 people, 29,423 households, and 19,272 families residing in the county. The population density was 77 people per square mile (30/km²). There were 33,091 housing units at an average density of 32 per square mile (12/km²). The racial makeup of the county was 93.33% White, 3.58% Black or African American, 0.36% Native American, 0.67% Asian, 0.02% Pacific Islander, 1.10% from other races, and 0.93% from two or more races. 2.46% of the population were Hispanic or Latino of any race. 23.7% were of French, 15.0% French Canadian, 12.5% American, 11.8% Irish, 7.6% English and 5.5% German ancestry according to Census 2000. 94.1% spoke English, 2.8% French and 1.7% Spanish as their first language.
There were 29,423 households out of which 32.00% had children under the age of 18 living with them, 51.00% were married couples living together, 10.20% had a female householder with no husband present, and 34.50% were non-families. 26.30% of all households were made up of individuals and 10.00% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 2.98.
In the county the population was spread out with 23.00% under the age of 18, 12.40% from 18 to 24, 30.60% from 25 to 44, 22.10% from 45 to 64, and 11.90% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 104.90 males. For every 100 females age 18 and over, there were 104.60 males.
The median income for a household in the county was $37,028, and the median income for a family was $45,732. Males had a median income of $33,788 versus $25,520 for females. The per capita income for the county was $17,946. About 9.40% of families and 13.90% of the population were below the poverty line, including 15.30% of those under age 18 and 11.40% of those age 65 or over.