As of the census of 2000, there were 47,722 people, 18,350 households, and 12,936 families residing in the county. The population density was 65 people per square mile (25/km²). There were 30,593 housing units at an average density of 42 per square mile (16/km²). The racial makeup of the county was 96.73% White, 1.59% Black or African American, 0.14% Native American, 0.38% Asian, 0.52% from other races, and 0.64% from two or more races. 1.70% of the population were Hispanic or Latino of any race. 24.2% were of German, 16.4% Irish, 11.4% Italian, 10.9% English, 8.5% Polish and 6.2% American ancestry according to Census 2000.
There were 18,350 households out of which 30.30% had children under the age of 18 living with them, 57.20% were married couples living together, 8.90% had a female householder with no husband present, and 29.50% were non-families. 25.20% of all households were made up of individuals and 12.20% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 2.98.
In the county, the population was spread out with 24.00% under the age of 18, 6.10% from 18 to 24, 26.80% from 25 to 44, 25.60% from 45 to 64, and 17.50% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 100.70 males. For every 100 females age 18 and over, there were 98.50 males.