Cheshire was one of the five original counties of New Hampshire, and is named for Cheshire in England. It was organized in 1771 at Keene.
As of the census of 2000, there were 73,825 people, 28,299 households, and 18,790 families residing in the county. The population density was 104 people per square mile (40/km²). There were 31,876 housing units at an average density of 45 per square mile (17/km²). The racial makeup of the county was 97.75% White, 0.37% Black or African American, 0.31% Native American, 0.47% Asian, 0.04% Pacific Islander, 0.18% from other races, and 0.89% from two or more races. 0.72% of the population were Hispanic or Latino of any race. 16.2% were of English, 13.1% French, 12.7% Irish, 9.3% American, 8.7% French Canadian, 6.7% Italian and 6.5% German ancestry according to Census 2000. 95.5% spoke English, 1.4% French and 1.2% Spanish as their first language.
There were 28,299 households out of which 30.60% had children under the age of 18 living with them, 53.50% were married couples living together, 9.00% had a female householder with no husband present, and 33.60% were non-families. 25.50% of all households were made up of individuals and 9.60% 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 2.96.
In the county the population was spread out with 23.30% under the age of 18, 11.70% from 18 to 24, 27.00% from 25 to 44, 24.30% from 45 to 64, and 13.70% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 94.90 males. For every 100 females age 18 and over, there were 91.70 males.
The median income for a household in the county was $42,382, and the median income for a family was $51,043. Males had a median income of $33,821 versus $25,328 for females. The per capita income for the county was $20,685. About 4.40% of families and 8.00% of the population were below the poverty line, including 8.50% of those under age 18 and 6.30% of those age 65 or over.