| | Tuscumbia, AL | Killen, AL | United States |
| Population | 8,977 | 1,209 | 329,725,481 |
| Female Population | 54.6% | 53.3% | 50.5% |
| Male Population | 45.4% | 46.7% | 49.5% |
| Median Age | 37.1 | 42.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 8,592 | 999 | 309,327,143 |
| Population - 2000 | 7,856 | 1,119 | 285,036,114 |
| Population - 1990 | 8,413 | 1,047 | 251,960,433 |
| Pop. 2000 to Now | 7.7% | -14.0% | 15.6% |
| Pop. 1990 to Now | 0.6% | -8.1% | 30.8% |
| space4 | | | |
| Population Density | 973.5 | 597.0 | 93.4 |
| Land Area | 9.2 | 2.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Tuscumbia, AL | Killen, AL | United States |
| Age 0 to 4 | 8.0% | 5.8% | 5.9% |
| Age 5 to 9 | 7.6% | 8.1% | 6.1% |
| Age 10 to 14 | 7.5% | 5.8% | 6.6% |
| Age 15 to 17 | 3.4% | 2.0% | 3.9% |
| Age 18 to 20 | 4.2% | 3.6% | 4.0% |
| Age 21 to 24 | 2.8% | 5.7% | 5.2% |
| Age 25 to 34 | 13.7% | 9.3% | 13.8% |
| Age 35 to 44 | 10.8% | 13.3% | 12.9% |
| Age 45 to 54 | 11.9% | 12.8% | 12.6% |
| Age 55 to 59 | 4.9% | 5.1% | 6.7% |
| Age 60 to 64 | 6.8% | 6.5% | 6.3% |
| Age 65 to 74 | 9.4% | 14.0% | 9.6% |
| Age 75 to 84 | 7.3% | 4.6% | 4.5% |
| Age 85 and over | 1.8% | 3.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Tuscumbia, AL | Killen, AL | United States |
| White | 67.9% | 91.3% | 59.4% |
| Black | 23.2% | 4.1% | 12.2% |
| Asian | 0.7% | 0.0% | 5.6% |
| Native American | 0.6% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 3.3% | 2.0% | 3.2% |
| Hispanic | 4.2% | 2.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Tuscumbia, AL | Killen, AL | United States |
| Married Population | 46.2% | 50.7% | 49.8% |
| Currently Married | 44.9% | 49.2% | 48.0% |
| Married but Separated | 1.2% | 1.4% | 1.8% |
| Single Population | 53.8% | 49.3% | 50.2% |
| Never Married | 28.9% | 21.0% | 33.8% |
| Divorced | 15.5% | 17.4% | 10.8% |
| Widowed | 9.4% | 10.9% | 5.6% |
| space5 | | | |
| Household Size | 2.43 | 2.80 | 2.60 |
| Households | 3,608 | 432 | 124,010,992 |
| Family Households | 2,190 | 320 | 80,755,759 |
| Married couple, w/children | 28.7% | 31.3% | 30.5% |
| Married couple, no children | 37.9% | 41.9% | 42.9% |
| Non Family Households | 1,418 | 112 | 43,255,233 |
| Single householder, w/children | 22.6% | 7.2% | 15.8% |
| Single householder, no children | 10.8% | 19.7% | 10.8% |