| | Centerville, IA | Galena, IL | United States |
| Population | 5,353 | 3,212 | 329,725,481 |
| Female Population | 54.4% | 53.6% | 50.5% |
| Male Population | 45.6% | 46.5% | 49.5% |
| Median Age | 47 | 56.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 5,615 | 3,409 | 309,327,143 |
| Population - 2000 | 5,924 | 3,460 | 285,036,114 |
| Population - 1990 | 5,936 | 3,647 | 251,960,433 |
| Pop. 2000 to Now | -8.6% | -8.9% | 15.6% |
| Pop. 1990 to Now | -8.8% | -13.6% | 30.8% |
| space4 | | | |
| Population Density | 1,110.6 | 720.2 | 93.4 |
| Land Area | 4.8 | 4.5 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Centerville, IA | Galena, IL | United States |
| Age 0 to 4 | 4.2% | 2.4% | 5.9% |
| Age 5 to 9 | 7.4% | 3.9% | 6.1% |
| Age 10 to 14 | 6.9% | 4.8% | 6.6% |
| Age 15 to 17 | 2.9% | 4.0% | 3.9% |
| Age 18 to 20 | 4.0% | 1.5% | 4.0% |
| Age 21 to 24 | 3.4% | 3.2% | 5.2% |
| Age 25 to 34 | 7.2% | 5.4% | 13.8% |
| Age 35 to 44 | 12.8% | 15.3% | 12.9% |
| Age 45 to 54 | 10.8% | 7.6% | 12.6% |
| Age 55 to 59 | 7.7% | 7.7% | 6.7% |
| Age 60 to 64 | 9.5% | 10.8% | 6.3% |
| Age 65 to 74 | 12.0% | 19.7% | 9.6% |
| Age 75 to 84 | 5.4% | 6.4% | 4.5% |
| Age 85 and over | 5.6% | 7.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Centerville, IA | Galena, IL | United States |
| White | 94.6% | 87.6% | 59.4% |
| Black | 0.1% | 0.5% | 12.2% |
| Asian | 0.1% | 0.3% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.6% | 0.0% | 3.2% |
| Hispanic | 2.6% | 11.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Centerville, IA | Galena, IL | United States |
| Married Population | 42.7% | 51.1% | 49.8% |
| Currently Married | 42.7% | 51.1% | 48.0% |
| Married but Separated | 0.0% | 0.0% | 1.8% |
| Single Population | 57.3% | 48.9% | 50.2% |
| Never Married | 28.6% | 23.8% | 33.8% |
| Divorced | 16.3% | 11.8% | 10.8% |
| Widowed | 12.4% | 13.3% | 5.6% |
| space5 | | | |
| Household Size | 2.34 | 1.85 | 2.60 |
| Households | 2,242 | 1,690 | 124,010,992 |
| Family Households | 1,244 | 845 | 80,755,759 |
| Married couple, w/children | 23.2% | 18.6% | 30.5% |
| Married couple, no children | 49.0% | 58.6% | 42.9% |
| Non Family Households | 998 | 845 | 43,255,233 |
| Single householder, w/children | 16.2% | 12.5% | 15.8% |
| Single householder, no children | 11.7% | 10.3% | 10.8% |