| | Harlem, GA | Middleburg, FL | United States |
| Population | 3,567 | 12,127 | 329,725,481 |
| Female Population | 58.9% | 44.9% | 50.5% |
| Male Population | 41.1% | 55.1% | 49.5% |
| Median Age | 31.8 | 43.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,680 | 12,888 | 309,327,143 |
| Population - 2000 | 1,814 | 10,338 | 285,036,114 |
| Population - 1990 | 2,199 | 6,223 | 251,960,433 |
| Pop. 2000 to Now | 95.5% | 41.0% | 15.6% |
| Pop. 1990 to Now | 61.3% | 134.3% | 30.8% |
| space4 | | | |
| Population Density | 565.7 | 617.8 | 93.4 |
| Land Area | 6.3 | 19.6 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Harlem, GA | Middleburg, FL | United States |
| Age 0 to 4 | 8.1% | 5.6% | 5.9% |
| Age 5 to 9 | 6.8% | 6.4% | 6.1% |
| Age 10 to 14 | 13.7% | 5.3% | 6.6% |
| Age 15 to 17 | 4.8% | 4.6% | 3.9% |
| Age 18 to 20 | 2.0% | 2.7% | 4.0% |
| Age 21 to 24 | 3.6% | 4.7% | 5.2% |
| Age 25 to 34 | 13.7% | 13.2% | 13.8% |
| Age 35 to 44 | 16.6% | 9.8% | 12.9% |
| Age 45 to 54 | 4.1% | 17.5% | 12.6% |
| Age 55 to 59 | 4.8% | 8.8% | 6.7% |
| Age 60 to 64 | 9.7% | 7.3% | 6.3% |
| Age 65 to 74 | 10.0% | 9.2% | 9.6% |
| Age 75 to 84 | 2.1% | 3.6% | 4.5% |
| Age 85 and over | 0.1% | 1.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Harlem, GA | Middleburg, FL | United States |
| White | 66.4% | 86.8% | 59.4% |
| Black | 29.2% | 3.8% | 12.2% |
| Asian | 0.0% | 0.3% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.1% | 0.4% |
| Two or More Races | 3.4% | 3.2% | 3.2% |
| Hispanic | 1.0% | 5.7% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Harlem, GA | Middleburg, FL | United States |
| Married Population | 45.5% | 57.4% | 49.8% |
| Currently Married | 45.5% | 55.9% | 48.0% |
| Married but Separated | 0.0% | 1.4% | 1.8% |
| Single Population | 54.5% | 42.6% | 50.2% |
| Never Married | 27.7% | 22.7% | 33.8% |
| Divorced | 11.8% | 15.7% | 10.8% |
| Widowed | 15.0% | 4.2% | 5.6% |
| space5 | | | |
| Household Size | 2.90 | 2.51 | 2.60 |
| Households | 1,226 | 4,824 | 124,010,992 |
| Family Households | 789 | 3,457 | 80,755,759 |
| Married couple, w/children | 22.6% | 31.6% | 30.5% |
| Married couple, no children | 26.9% | 45.8% | 42.9% |
| Non Family Households | 437 | 1,367 | 43,255,233 |
| Single householder, w/children | 46.4% | 11.7% | 15.8% |
| Single householder, no children | 4.2% | 10.8% | 10.8% |