| | Carlyle, IL | Heflin, AL | United States |
| Population | 3,290 | 3,416 | 329,725,481 |
| Female Population | 50.3% | 55.7% | 50.5% |
| Male Population | 49.7% | 44.3% | 49.5% |
| Median Age | 35.3 | 42 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,301 | 3,493 | 309,327,143 |
| Population - 2000 | 3,406 | 3,002 | 285,036,114 |
| Population - 1990 | 3,474 | 2,906 | 251,960,433 |
| Pop. 2000 to Now | -7.6% | 13.5% | 15.6% |
| Pop. 1990 to Now | -9.4% | 17.3% | 30.8% |
| space4 | | | |
| Population Density | 970.8 | 212.4 | 93.4 |
| Land Area | 3.4 | 16.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Carlyle, IL | Heflin, AL | United States |
| Age 0 to 4 | 5.6% | 6.4% | 5.9% |
| Age 5 to 9 | 7.2% | 5.0% | 6.1% |
| Age 10 to 14 | 5.8% | 7.9% | 6.6% |
| Age 15 to 17 | 1.9% | 3.6% | 3.9% |
| Age 18 to 20 | 9.2% | 2.1% | 4.0% |
| Age 21 to 24 | 6.6% | 2.3% | 5.2% |
| Age 25 to 34 | 13.1% | 9.3% | 13.8% |
| Age 35 to 44 | 13.1% | 18.4% | 12.9% |
| Age 45 to 54 | 10.0% | 9.1% | 12.6% |
| Age 55 to 59 | 4.8% | 5.6% | 6.7% |
| Age 60 to 64 | 4.3% | 9.0% | 6.3% |
| Age 65 to 74 | 10.8% | 14.9% | 9.6% |
| Age 75 to 84 | 5.5% | 3.4% | 4.5% |
| Age 85 and over | 2.3% | 3.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Carlyle, IL | Heflin, AL | United States |
| White | 89.4% | 87.6% | 59.4% |
| Black | 1.8% | 6.6% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.2% | 0.4% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 6.7% | 3.9% | 3.2% |
| Hispanic | 1.9% | 1.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Carlyle, IL | Heflin, AL | United States |
| Married Population | 47.0% | 44.9% | 49.8% |
| Currently Married | 46.3% | 42.0% | 48.0% |
| Married but Separated | 0.7% | 2.9% | 1.8% |
| Single Population | 53.0% | 55.1% | 50.2% |
| Never Married | 36.5% | 23.1% | 33.8% |
| Divorced | 13.0% | 18.6% | 10.8% |
| Widowed | 3.5% | 13.4% | 5.6% |
| space5 | | | |
| Household Size | 2.42 | 2.50 | 2.60 |
| Households | 1,278 | 1,308 | 124,010,992 |
| Family Households | 920 | 793 | 80,755,759 |
| Married couple, w/children | 32.0% | 24.2% | 30.5% |
| Married couple, no children | 35.1% | 35.1% | 42.9% |
| Non Family Households | 358 | 515 | 43,255,233 |
| Single householder, w/children | 17.4% | 17.2% | 15.8% |
| Single householder, no children | 15.5% | 23.6% | 10.8% |