| | Bolivar, WV | Essex, MD | United States |
| Population | 1,290 | 40,710 | 329,725,481 |
| Female Population | 45.7% | 53.3% | 50.5% |
| Male Population | 54.3% | 46.7% | 49.5% |
| Median Age | 40.2 | 38.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,039 | 38,790 | 309,327,143 |
| Population - 2000 | 1,045 | 39,078 | 285,036,114 |
| Population - 1990 | 1,013 | 40,872 | 251,960,433 |
| Pop. 2000 to Now | -2.6% | 0.9% | 15.6% |
| Pop. 1990 to Now | 0.5% | -3.6% | 30.8% |
| space4 | | | |
| Population Density | 2,979.2 | 4,397.3 | 93.4 |
| Land Area | 0.4 | 9.3 | 3,531,905.4 |
| Water Area | 0.0 | 2.6 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Bolivar, WV | Essex, MD | United States |
| Age 0 to 4 | 3.6% | 6.1% | 5.9% |
| Age 5 to 9 | 3.9% | 6.7% | 6.1% |
| Age 10 to 14 | 9.8% | 6.4% | 6.6% |
| Age 15 to 17 | 4.4% | 3.7% | 3.9% |
| Age 18 to 20 | 2.0% | 2.7% | 4.0% |
| Age 21 to 24 | 8.2% | 3.9% | 5.2% |
| Age 25 to 34 | 10.7% | 15.8% | 13.8% |
| Age 35 to 44 | 12.2% | 10.9% | 12.9% |
| Age 45 to 54 | 10.9% | 13.8% | 12.6% |
| Age 55 to 59 | 13.5% | 7.2% | 6.7% |
| Age 60 to 64 | 7.3% | 7.1% | 6.3% |
| Age 65 to 74 | 8.4% | 9.4% | 9.6% |
| Age 75 to 84 | 3.9% | 4.5% | 4.5% |
| Age 85 and over | 1.2% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Bolivar, WV | Essex, MD | United States |
| White | 86.8% | 57.8% | 59.4% |
| Black | 2.3% | 29.4% | 12.2% |
| Asian | 0.8% | 1.7% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.8% | 0.3% | 0.4% |
| Two or More Races | 5.1% | 4.4% | 3.2% |
| Hispanic | 4.2% | 6.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Bolivar, WV | Essex, MD | United States |
| Married Population | 48.8% | 42.2% | 49.8% |
| Currently Married | 47.3% | 39.4% | 48.0% |
| Married but Separated | 1.5% | 2.8% | 1.8% |
| Single Population | 51.2% | 57.8% | 50.2% |
| Never Married | 30.4% | 35.9% | 33.8% |
| Divorced | 14.9% | 14.2% | 10.8% |
| Widowed | 5.9% | 7.8% | 5.6% |
| space5 | | | |
| Household Size | 2.41 | 2.58 | 2.60 |
| Households | 535 | 15,702 | 124,010,992 |
| Family Households | 280 | 9,472 | 80,755,759 |
| Married couple, w/children | 36.1% | 21.8% | 30.5% |
| Married couple, no children | 43.9% | 37.5% | 42.9% |
| Non Family Households | 255 | 6,230 | 43,255,233 |
| Single householder, w/children | 13.2% | 25.9% | 15.8% |
| Single householder, no children | 6.8% | 14.8% | 10.8% |