Pike County is located on the highlands between the Illinois River on the eastern border, and the Mississippi River on the west. It has one interstate highway, I-72, with bridges spanning both rivers to enter the county.
Pike County, Illinois, is one of the few counties in the United States to border as many as 9 counties. Illinois has two such counties--Pike and LaSalle. It is also one of the few counties in the United States to border its namesake in another state--in this case, Pike County, Missouri. Illinois has another such county--Vermilion County, Illinois, which borders Vermillion County, Indiana (note that although they are spelled differently, they are both named for the Vermilion River).
Prior to the coming of the first settler to Pike County there had been French traders, hunters, and travelers passing through the native forests and beautiful prairies. Originally Pike County began on the south junction of the Illinois and Mississippi rivers. The east boundary was the Illinois River north to the Kankakee River to the Indiana State line on north to Wisconsin state line and then west to the Mississippi River to the original point at the south end. The first county seat was Cole's Grove, a post town, in what later became Calhoun County. The Gazetteer of Illinois and Missouri published in 1822 mentioned Chicago as a village of Pike County, containing 12 or 15 houses and about 60 or 70 inhabitants.
Frank McWorter was an early settler in Pike County after investing in land sight unseen and purchasing the first few members of his family out of slavery in Kentucky. In 1836 he founded the town of New Philadelphia, near Barry, Illinois, returning to Kentucky over several decades to free other offspring. The town site is now an archaeological dig.
There were 6,876 households out of which 30.50% had children under the age of 18 living with them, 58.50% were married couples living together, 7.80% had a female householder with no husband present, and 30.50% were non-families. 27.80% of all households were made up of individuals and 16.10% had someone living alone who was 65 years of age or older. The average household size was 2.42 and the average family size was 2.94.
In the county the population was spread out with 24.10% under the age of 18, 7.80% from 18 to 24, 25.70% from 25 to 44, 23.20% from 45 to 64, and 19.20% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 98.10 males. For every 100 females age 18 and over, there were 95.30 males.
The median income for a household in the county was $31,127, and the median income for a family was $38,583. Males had a median income of $27,687 versus $18,440 for females. The per capita income for the county was $15,946. About 9.80% of families and 12.40% of the population were below the poverty line, including 14.70% of those under age 18 and 11.40% of those age 65 or over.