| | Washington, IL | East Peoria, IL | United States |
| Population | 16,008 | 22,707 | 329,725,481 |
| Female Population | 51.6% | 49.2% | 50.5% |
| Male Population | 48.4% | 50.8% | 49.5% |
| Median Age | 37.4 | 41.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 15,277 | 23,468 | 309,327,143 |
| Population - 2000 | 10,841 | 22,638 | 285,036,114 |
| Population - 1990 | 10,099 | 21,378 | 251,960,433 |
| Pop. 2000 to Now | 51.2% | -1.3% | 15.6% |
| Pop. 1990 to Now | 62.3% | 4.5% | 30.8% |
| space4 | | | |
| Population Density | 1,892.4 | 1,125.9 | 93.4 |
| Land Area | 8.5 | 20.2 | 3,531,905.4 |
| Water Area | 0.0 | 1.8 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Washington, IL | East Peoria, IL | United States |
| Age 0 to 4 | 5.9% | 5.9% | 5.9% |
| Age 5 to 9 | 9.6% | 6.1% | 6.1% |
| Age 10 to 14 | 9.3% | 5.3% | 6.6% |
| Age 15 to 17 | 5.5% | 2.8% | 3.9% |
| Age 18 to 20 | 3.3% | 3.6% | 4.0% |
| Age 21 to 24 | 2.1% | 5.2% | 5.2% |
| Age 25 to 34 | 11.7% | 11.8% | 13.8% |
| Age 35 to 44 | 14.7% | 13.1% | 12.9% |
| Age 45 to 54 | 11.3% | 13.3% | 12.6% |
| Age 55 to 59 | 5.1% | 6.2% | 6.7% |
| Age 60 to 64 | 6.0% | 7.1% | 6.3% |
| Age 65 to 74 | 7.9% | 12.0% | 9.6% |
| Age 75 to 84 | 5.1% | 5.8% | 4.5% |
| Age 85 and over | 2.6% | 1.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Washington, IL | East Peoria, IL | United States |
| White | 94.4% | 92.2% | 59.4% |
| Black | 0.6% | 1.6% | 12.2% |
| Asian | 1.2% | 2.4% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.2% | 0.1% | 0.4% |
| Two or More Races | 1.3% | 1.5% | 3.2% |
| Hispanic | 2.4% | 2.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Washington, IL | East Peoria, IL | United States |
| Married Population | 60.2% | 56.9% | 49.8% |
| Currently Married | 59.1% | 55.8% | 48.0% |
| Married but Separated | 1.1% | 1.1% | 1.8% |
| Single Population | 39.8% | 43.1% | 50.2% |
| Never Married | 23.9% | 26.3% | 33.8% |
| Divorced | 7.7% | 10.8% | 10.8% |
| Widowed | 8.2% | 6.0% | 5.6% |
| space5 | | | |
| Household Size | 2.65 | 2.31 | 2.60 |
| Households | 6,013 | 9,658 | 124,010,992 |
| Family Households | 4,178 | 5,975 | 80,755,759 |
| Married couple, w/children | 40.0% | 30.5% | 30.5% |
| Married couple, no children | 42.3% | 54.6% | 42.9% |
| Non Family Households | 1,835 | 3,683 | 43,255,233 |
| Single householder, w/children | 12.4% | 10.5% | 15.8% |
| Single householder, no children | 5.4% | 4.4% | 10.8% |