| | Rockford, TN | Millersville, TN | United States |
| Population | 833 | 6,099 | 329,725,481 |
| Female Population | 54.4% | 51.2% | 50.5% |
| Male Population | 45.6% | 48.8% | 49.5% |
| Median Age | 41.8 | 39.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 856 | 6,401 | 309,327,143 |
| Population - 2000 | 798 | 5,308 | 285,036,114 |
| Population - 1990 | 646 | 2,575 | 251,960,433 |
| Pop. 2000 to Now | 6.6% | 28.1% | 15.6% |
| Pop. 1990 to Now | 31.7% | 164.0% | 30.8% |
| space4 | | | |
| Population Density | 261.7 | 441.9 | 93.4 |
| Land Area | 3.2 | 13.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Rockford, TN | Millersville, TN | United States |
| Age 0 to 4 | 5.0% | 5.0% | 5.9% |
| Age 5 to 9 | 4.6% | 7.0% | 6.1% |
| Age 10 to 14 | 6.1% | 5.3% | 6.6% |
| Age 15 to 17 | 4.9% | 3.5% | 3.9% |
| Age 18 to 20 | 7.0% | 2.3% | 4.0% |
| Age 21 to 24 | 1.3% | 5.1% | 5.2% |
| Age 25 to 34 | 6.5% | 14.1% | 13.8% |
| Age 35 to 44 | 16.3% | 12.6% | 12.9% |
| Age 45 to 54 | 10.8% | 10.2% | 12.6% |
| Age 55 to 59 | 7.7% | 8.0% | 6.7% |
| Age 60 to 64 | 8.0% | 7.2% | 6.3% |
| Age 65 to 74 | 14.2% | 15.6% | 9.6% |
| Age 75 to 84 | 6.4% | 2.6% | 4.5% |
| Age 85 and over | 1.2% | 1.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | Rockford, TN | Millersville, TN | United States |
| White | 87.2% | 73.5% | 59.4% |
| Black | 0.0% | 11.7% | 12.2% |
| Asian | 0.0% | 0.8% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 1.1% | 0.4% |
| Two or More Races | 5.4% | 2.6% | 3.2% |
| Hispanic | 7.4% | 10.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Rockford, TN | Millersville, TN | United States |
| Married Population | 57.1% | 45.0% | 49.8% |
| Currently Married | 54.6% | 40.1% | 48.0% |
| Married but Separated | 2.6% | 4.9% | 1.8% |
| Single Population | 42.9% | 55.0% | 50.2% |
| Never Married | 23.5% | 29.6% | 33.8% |
| Divorced | 12.3% | 20.4% | 10.8% |
| Widowed | 7.1% | 5.0% | 5.6% |
| space5 | | | |
| Household Size | 2.42 | 2.33 | 2.60 |
| Households | 344 | 2,613 | 124,010,992 |
| Family Households | 267 | 1,424 | 80,755,759 |
| Married couple, w/children | 24.3% | 26.6% | 30.5% |
| Married couple, no children | 50.6% | 41.3% | 42.9% |
| Non Family Households | 77 | 1,189 | 43,255,233 |
| Single householder, w/children | 17.2% | 24.5% | 15.8% |
| Single householder, no children | 7.9% | 7.6% | 10.8% |