| | Riverdale, IL | Granite City, IL | United States |
| Population | 10,909 | 27,336 | 329,725,481 |
| Female Population | 51.4% | 49.2% | 50.5% |
| Male Population | 48.6% | 50.8% | 49.5% |
| Median Age | 32.7 | 39 | 38.4 |
| space3 | | | |
| Population - 2010 | 13,560 | 29,744 | 309,327,143 |
| Population - 2000 | 15,055 | 31,301 | 285,036,114 |
| Population - 1990 | 13,671 | 32,862 | 251,960,433 |
| Pop. 2000 to Now | -14.2% | -10.7% | 15.6% |
| Pop. 1990 to Now | -5.6% | -14.9% | 30.8% |
| space4 | | | |
| Population Density | 3,051.5 | 1,416.5 | 93.4 |
| Land Area | 3.6 | 19.3 | 3,531,905.4 |
| Water Area | 0.2 | 1.4 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Riverdale, IL | Granite City, IL | United States |
| Age 0 to 4 | 10.6% | 5.2% | 5.9% |
| Age 5 to 9 | 8.7% | 6.1% | 6.1% |
| Age 10 to 14 | 6.2% | 6.5% | 6.6% |
| Age 15 to 17 | 4.2% | 4.1% | 3.9% |
| Age 18 to 20 | 3.7% | 2.6% | 4.0% |
| Age 21 to 24 | 5.9% | 4.4% | 5.2% |
| Age 25 to 34 | 13.6% | 14.6% | 13.8% |
| Age 35 to 44 | 12.0% | 13.4% | 12.9% |
| Age 45 to 54 | 11.2% | 11.4% | 12.6% |
| Age 55 to 59 | 6.8% | 6.6% | 6.7% |
| Age 60 to 64 | 7.3% | 8.8% | 6.3% |
| Age 65 to 74 | 7.1% | 9.7% | 9.6% |
| Age 75 to 84 | 1.6% | 4.8% | 4.5% |
| Age 85 and over | 1.1% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Riverdale, IL | Granite City, IL | United States |
| White | 2.7% | 78.3% | 59.4% |
| Black | 87.6% | 10.1% | 12.2% |
| Asian | 0.0% | 0.5% | 5.6% |
| Native American | 0.1% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.2% | 0.4% |
| Two or More Races | 0.2% | 3.6% | 3.2% |
| Hispanic | 9.4% | 7.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Riverdale, IL | Granite City, IL | United States |
| Married Population | 26.7% | 43.5% | 49.8% |
| Currently Married | 22.7% | 41.1% | 48.0% |
| Married but Separated | 4.0% | 2.4% | 1.8% |
| Single Population | 73.3% | 56.5% | 50.2% |
| Never Married | 53.2% | 34.5% | 33.8% |
| Divorced | 13.3% | 15.0% | 10.8% |
| Widowed | 6.8% | 7.0% | 5.6% |
| space5 | | | |
| Household Size | 2.75 | 2.40 | 2.60 |
| Households | 3,951 | 11,291 | 124,010,992 |
| Family Households | 2,465 | 6,987 | 80,755,759 |
| Married couple, w/children | 16.1% | 21.5% | 30.5% |
| Married couple, no children | 15.9% | 40.5% | 42.9% |
| Non Family Households | 1,486 | 4,304 | 43,255,233 |
| Single householder, w/children | 39.0% | 23.9% | 15.8% |
| Single householder, no children | 28.9% | 14.1% | 10.8% |