| | Marshall, IL | Imperial, CA | United States |
| Population | 3,870 | 19,982 | 329,725,481 |
| Female Population | 52.7% | 52.1% | 50.5% |
| Male Population | 47.3% | 47.9% | 49.5% |
| Median Age | 41.8 | 28.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,941 | 14,817 | 309,327,143 |
| Population - 2000 | 3,771 | 7,560 | 285,036,114 |
| Population - 1990 | 3,555 | 4,113 | 251,960,433 |
| Pop. 2000 to Now | 0.1% | 160.1% | 15.6% |
| Pop. 1990 to Now | 6.2% | 378.1% | 30.8% |
| space4 | | | |
| Population Density | 1,037.8 | 3,277.9 | 93.4 |
| Land Area | 3.7 | 6.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Marshall, IL | Imperial, CA | United States |
| Age 0 to 4 | 5.6% | 11.6% | 5.9% |
| Age 5 to 9 | 8.8% | 9.1% | 6.1% |
| Age 10 to 14 | 3.0% | 9.6% | 6.6% |
| Age 15 to 17 | 4.0% | 7.0% | 3.9% |
| Age 18 to 20 | 4.5% | 5.2% | 4.0% |
| Age 21 to 24 | 4.1% | 4.5% | 5.2% |
| Age 25 to 34 | 12.3% | 9.6% | 13.8% |
| Age 35 to 44 | 10.8% | 12.8% | 12.9% |
| Age 45 to 54 | 13.0% | 10.4% | 12.6% |
| Age 55 to 59 | 6.5% | 4.5% | 6.7% |
| Age 60 to 64 | 5.2% | 6.0% | 6.3% |
| Age 65 to 74 | 11.3% | 5.8% | 9.6% |
| Age 75 to 84 | 6.4% | 3.0% | 4.5% |
| Age 85 and over | 4.6% | 0.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Marshall, IL | Imperial, CA | United States |
| White | 97.9% | 13.9% | 59.4% |
| Black | 0.4% | 1.7% | 12.2% |
| Asian | 0.0% | 3.4% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.2% | 0.4% |
| Two or More Races | 1.6% | 0.6% | 3.2% |
| Hispanic | 0.0% | 80.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Marshall, IL | Imperial, CA | United States |
| Married Population | 47.2% | 48.8% | 49.8% |
| Currently Married | 46.2% | 44.9% | 48.0% |
| Married but Separated | 1.0% | 3.9% | 1.8% |
| Single Population | 52.8% | 51.2% | 50.2% |
| Never Married | 29.9% | 40.0% | 33.8% |
| Divorced | 14.9% | 8.3% | 10.8% |
| Widowed | 7.9% | 2.9% | 5.6% |
| space5 | | | |
| Household Size | 2.29 | 3.88 | 2.60 |
| Households | 1,645 | 5,147 | 124,010,992 |
| Family Households | 1,130 | 3,943 | 80,755,759 |
| Married couple, w/children | 20.4% | 35.7% | 30.5% |
| Married couple, no children | 39.8% | 31.3% | 42.9% |
| Non Family Households | 515 | 1,204 | 43,255,233 |
| Single householder, w/children | 23.3% | 23.0% | 15.8% |
| Single householder, no children | 16.5% | 10.0% | 10.8% |