| | Jerseyville, IL | Hardin, IL | United States |
| Population | 7,674 | 758 | 329,725,481 |
| Female Population | 56.9% | 49.6% | 50.5% |
| Male Population | 43.1% | 50.4% | 49.5% |
| Median Age | 42.9 | 54.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 8,463 | 963 | 309,327,143 |
| Population - 2000 | 7,984 | 959 | 285,036,114 |
| Population - 1990 | 7,382 | 1,071 | 251,960,433 |
| Pop. 2000 to Now | 1.6% | -8.1% | 15.6% |
| Pop. 1990 to Now | 9.9% | -17.7% | 30.8% |
| space4 | | | |
| Population Density | 1,483.8 | 356.2 | 93.4 |
| Land Area | 5.2 | 2.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Jerseyville, IL | Hardin, IL | United States |
| Age 0 to 4 | 4.3% | 5.8% | 5.9% |
| Age 5 to 9 | 5.0% | 0.0% | 6.1% |
| Age 10 to 14 | 8.2% | 2.1% | 6.6% |
| Age 15 to 17 | 4.5% | 2.6% | 3.9% |
| Age 18 to 20 | 2.7% | 1.6% | 4.0% |
| Age 21 to 24 | 5.3% | 2.4% | 5.2% |
| Age 25 to 34 | 10.3% | 7.0% | 13.8% |
| Age 35 to 44 | 11.8% | 1.3% | 12.9% |
| Age 45 to 54 | 14.0% | 30.2% | 12.6% |
| Age 55 to 59 | 9.6% | 9.9% | 6.7% |
| Age 60 to 64 | 6.3% | 6.7% | 6.3% |
| Age 65 to 74 | 7.4% | 18.7% | 9.6% |
| Age 75 to 84 | 7.4% | 6.9% | 4.5% |
| Age 85 and over | 3.1% | 4.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Jerseyville, IL | Hardin, IL | United States |
| White | 95.7% | 96.8% | 59.4% |
| Black | 0.2% | 2.9% | 12.2% |
| Asian | 0.8% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.5% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.3% | 0.3% | 3.2% |
| Hispanic | 0.5% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Jerseyville, IL | Hardin, IL | United States |
| Married Population | 43.4% | 52.7% | 49.8% |
| Currently Married | 40.9% | 43.3% | 48.0% |
| Married but Separated | 2.5% | 9.5% | 1.8% |
| Single Population | 56.6% | 47.3% | 50.2% |
| Never Married | 26.8% | 21.2% | 33.8% |
| Divorced | 19.1% | 18.5% | 10.8% |
| Widowed | 10.7% | 7.6% | 5.6% |
| space5 | | | |
| Household Size | 2.49 | 3.07 | 2.60 |
| Households | 2,958 | 219 | 124,010,992 |
| Family Households | 1,767 | 155 | 80,755,759 |
| Married couple, w/children | 31.0% | 14.8% | 30.5% |
| Married couple, no children | 43.3% | 74.8% | 42.9% |
| Non Family Households | 1,191 | 64 | 43,255,233 |
| Single householder, w/children | 15.8% | 0.6% | 15.8% |
| Single householder, no children | 10.0% | 9.7% | 10.8% |