LaSalle County is part of the Ottawa–Streator Micropolitan Statistical Area.
2000 - 111,509 1990 - 106,913 1980 - 112,033 1970 - 111,409 1960 - 110,800 1950 - 100,610 1940 - 97,801 1930 - 97,695 1920 - 92,925 1910 - 90,132 1900 - 87,776 1890 - 80,798 1880 - 70,403 1870 - 60,792 1860 - 48,332 1850 - 17,815 1840 - 9,348
As of the census of 2000, there were 111,509 people, 43,417 households, and 29,827 families residing in the county. The population density was 98 people per square mile (38/km²). There were 46,438 housing units at an average density of 41 per square mile (16/km²). The racial makeup of the county was 94.97% White, 1.55% Black or African American, 0.17% Native American, 0.54% Asian, 0.02% Pacific Islander, 1.71% from other races, and 1.05% from two or more races. 5.19% of the population were Hispanic or Latino of any race. 25.8% were of German, 12.7% Irish, 8.8% Italian, 7.6% American, 7.3% English and 7.3% Polish ancestry according to Census 2000. 94.7% spoke English and 3.6% Spanish as their first language.
There were 43,417 households out of which 31.70% had children under the age of 18 living with them, 55.70% were married couples living together, 9.20% had a female householder with no husband present, and 31.30% were non-families. 27.40% of all households were made up of individuals and 13.30% had someone living alone who was 65 years of age or older. The average household size was 2.49 and the average family size was 3.04.
In the county the population was spread out with 25.20% under the age of 18, 8.10% from 18 to 24, 28.00% from 25 to 44, 22.30% from 45 to 64, and 16.40% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 97.90 males. For every 100 females age 18 and over, there were 96.40 males.
The median income for a household in the county was $40,308, and the median income for a family was $49,533. Males had a median income of $39,256 versus $22,097 for females. The per capita income for the county was $19,185. About 6.90% of families and 9.10% of the population were below the poverty line, including 13.10% of those under age 18 and 6.20% of those age 65 or over.