| | Seymour, TX | Mountain City, TN | United States |
| Population | 2,940 | 2,367 | 329,725,481 |
| Female Population | 52.5% | 52.9% | 50.5% |
| Male Population | 47.5% | 47.1% | 49.5% |
| Median Age | 45 | 44.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,721 | 2,514 | 309,327,143 |
| Population - 2000 | 2,908 | 2,383 | 285,036,114 |
| Population - 1990 | 3,185 | 2,169 | 251,960,433 |
| Pop. 2000 to Now | -12.1% | 2.6% | 15.6% |
| Pop. 1990 to Now | -19.7% | 12.7% | 30.8% |
| space4 | | | |
| Population Density | 1,005.8 | 702.4 | 93.4 |
| Land Area | 2.9 | 3.4 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Seymour, TX | Mountain City, TN | United States |
| Age 0 to 4 | 3.0% | 7.3% | 5.9% |
| Age 5 to 9 | 7.7% | 4.6% | 6.1% |
| Age 10 to 14 | 9.6% | 6.8% | 6.6% |
| Age 15 to 17 | 4.4% | 0.4% | 3.9% |
| Age 18 to 20 | 1.7% | 1.1% | 4.0% |
| Age 21 to 24 | 3.8% | 5.2% | 5.2% |
| Age 25 to 34 | 7.2% | 15.4% | 13.8% |
| Age 35 to 44 | 12.7% | 9.6% | 12.9% |
| Age 45 to 54 | 10.2% | 9.3% | 12.6% |
| Age 55 to 59 | 10.0% | 4.6% | 6.7% |
| Age 60 to 64 | 7.8% | 9.2% | 6.3% |
| Age 65 to 74 | 10.5% | 9.0% | 9.6% |
| Age 75 to 84 | 9.5% | 12.6% | 4.5% |
| Age 85 and over | 2.1% | 5.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Seymour, TX | Mountain City, TN | United States |
| White | 72.2% | 84.8% | 59.4% |
| Black | 4.2% | 3.8% | 12.2% |
| Asian | 0.0% | 1.0% | 5.6% |
| Native American | 0.1% | 0.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.5% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 6.7% | 2.6% | 3.2% |
| Hispanic | 16.3% | 7.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Seymour, TX | Mountain City, TN | United States |
| Married Population | 56.2% | 42.5% | 49.8% |
| Currently Married | 53.4% | 39.1% | 48.0% |
| Married but Separated | 2.7% | 3.4% | 1.8% |
| Single Population | 43.8% | 57.5% | 50.2% |
| Never Married | 22.5% | 25.0% | 33.8% |
| Divorced | 10.4% | 20.2% | 10.8% |
| Widowed | 10.9% | 12.2% | 5.6% |
| space5 | | | |
| Household Size | 2.35 | 2.09 | 2.60 |
| Households | 1,225 | 1,022 | 124,010,992 |
| Family Households | 788 | 513 | 80,755,759 |
| Married couple, w/children | 32.2% | 18.9% | 30.5% |
| Married couple, no children | 46.1% | 46.2% | 42.9% |
| Non Family Households | 437 | 509 | 43,255,233 |
| Single householder, w/children | 18.3% | 24.6% | 15.8% |
| Single householder, no children | 3.4% | 10.3% | 10.8% |