It is named for Colonel John Allen, who was killed leading his men at the Battle of Frenchtown, during the War of 1812. Although it has also been claimed the county was named for Revolutionary War soldier Ethan Allen, the weight of the evidence in favor of John Allen led the General Assembly to declare that the county was named for him. The county seat is Lima.
2006 105,788 2000 108,473 1990 109,755 1980 112,241 1970 111,144 1960 103,691 1950 88,183 1940 73,303 1930 69,419 1920 68,223 1910 56,580 1900 47,976 1890 40,644 1880 31,314 1870 23,623 1860 19,185 1850 12,109 1840 9,079 1830 578
As of the census of 2000, there were 108,473 people, 40,646 households, and 28,208 families residing in the county. The population density was 268 people per square mile (104/km²). There were 44,245 housing units at an average density of 109 per square mile (42/km²). The racial makeup of the county was 84.95% White, 12.19% Black or African American, 0.21% Native American, 0.55% Asian, 0.01% Pacific Islander, 0.63% from other races, and 1.45% from two or more races. 1.42% of the population were Hispanic or Latino of any race. 33.8% were of German, 14.2% American, 8.8% Irish and 6.6% English ancestry according to Census 2000.
There were 40,646 households out of which 32.90% had children under the age of 18 living with them, 53.00% were married couples living together, 12.40% had a female householder with no husband present, and 30.60% were non-families. 26.30% of all households were made up of individuals and 11.20% had someone living alone who was 65 years of age or older. The average household size was 2.52 and the average family size was 3.05.
In the county the population was spread out with 25.90% under the age of 18, 9.90% from 18 to 24, 27.60% from 25 to 44, 22.40% from 45 to 64, and 14.20% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 100.00 males. For every 100 females age 18 and over, there were 98.00 males.
The median income for a household in the county was $37,048, and the median income for a family was $44,723. Males had a median income of $35,546 versus $23,537 for females. The per capita income for the county was $17,511. About 9.60% of families and 12.10% of the population were below the poverty line, including 17.00% of those under age 18 and 9.60% of those age 65 or over.