| | Pekin, IL | Mapleton, IL | United States |
| Population | 32,398 | 308 | 329,725,481 |
| Female Population | 50.9% | 52.6% | 50.5% |
| Male Population | 49.1% | 47.4% | 49.5% |
| Median Age | 41.5 | 34.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 34,041 | 273 | 309,327,143 |
| Population - 2000 | 33,857 | 227 | 285,036,114 |
| Population - 1990 | 32,254 | 216 | 251,960,433 |
| Pop. 2000 to Now | -6.1% | 18.1% | 15.6% |
| Pop. 1990 to Now | -1.4% | 24.1% | 30.8% |
| space4 | | | |
| Population Density | 2,216.0 | 325.9 | 93.4 |
| Land Area | 14.6 | 0.9 | 3,531,905.4 |
| Water Area | 0.8 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Pekin, IL | Mapleton, IL | United States |
| Age 0 to 4 | 5.9% | 5.2% | 5.9% |
| Age 5 to 9 | 6.8% | 4.5% | 6.1% |
| Age 10 to 14 | 5.0% | 13.6% | 6.6% |
| Age 15 to 17 | 3.5% | 9.7% | 3.9% |
| Age 18 to 20 | 2.5% | 4.2% | 4.0% |
| Age 21 to 24 | 4.9% | 4.9% | 5.2% |
| Age 25 to 34 | 13.9% | 8.8% | 13.8% |
| Age 35 to 44 | 11.5% | 14.6% | 12.9% |
| Age 45 to 54 | 12.9% | 11.4% | 12.6% |
| Age 55 to 59 | 7.2% | 3.2% | 6.7% |
| Age 60 to 64 | 7.7% | 5.5% | 6.3% |
| Age 65 to 74 | 11.1% | 13.6% | 9.6% |
| Age 75 to 84 | 4.4% | 0.6% | 4.5% |
| Age 85 and over | 2.6% | 0.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Pekin, IL | Mapleton, IL | United States |
| White | 90.8% | 99.7% | 59.4% |
| Black | 3.0% | 0.0% | 12.2% |
| Asian | 0.5% | 0.0% | 5.6% |
| Native American | 0.2% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.1% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.8% | 0.3% | 3.2% |
| Hispanic | 2.6% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Pekin, IL | Mapleton, IL | United States |
| Married Population | 43.2% | 43.6% | 49.8% |
| Currently Married | 41.5% | 39.4% | 48.0% |
| Married but Separated | 1.6% | 4.2% | 1.8% |
| Single Population | 56.8% | 56.4% | 50.2% |
| Never Married | 33.2% | 39.4% | 33.8% |
| Divorced | 15.0% | 8.5% | 10.8% |
| Widowed | 8.7% | 8.5% | 5.6% |
| space5 | | | |
| Household Size | 2.24 | 2.66 | 2.60 |
| Households | 13,706 | 116 | 124,010,992 |
| Family Households | 7,504 | 82 | 80,755,759 |
| Married couple, w/children | 26.0% | 19.5% | 30.5% |
| Married couple, no children | 42.5% | 32.9% | 42.9% |
| Non Family Households | 6,202 | 34 | 43,255,233 |
| Single householder, w/children | 20.1% | 36.6% | 15.8% |
| Single householder, no children | 11.4% | 11.0% | 10.8% |