| | Nashua, IA | Mountain City, TN | United States |
| Population | 1,505 | 2,367 | 329,725,481 |
| Female Population | 49.0% | 52.9% | 50.5% |
| Male Population | 51.0% | 47.1% | 49.5% |
| Median Age | 36.2 | 44.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,653 | 2,514 | 309,327,143 |
| Population - 2000 | 1,618 | 2,383 | 285,036,114 |
| Population - 1990 | 1,476 | 2,169 | 251,960,433 |
| Pop. 2000 to Now | -2.9% | 2.6% | 15.6% |
| Pop. 1990 to Now | 6.4% | 12.7% | 30.8% |
| space4 | | | |
| Population Density | 522.8 | 702.4 | 93.4 |
| Land Area | 2.9 | 3.4 | 3,531,905.4 |
| Water Area | 0.3 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Nashua, IA | Mountain City, TN | United States |
| Age 0 to 4 | 5.2% | 7.3% | 5.9% |
| Age 5 to 9 | 5.3% | 4.6% | 6.1% |
| Age 10 to 14 | 12.2% | 6.8% | 6.6% |
| Age 15 to 17 | 3.4% | 0.4% | 3.9% |
| Age 18 to 20 | 1.7% | 1.1% | 4.0% |
| Age 21 to 24 | 7.5% | 5.2% | 5.2% |
| Age 25 to 34 | 11.6% | 15.4% | 13.8% |
| Age 35 to 44 | 15.7% | 9.6% | 12.9% |
| Age 45 to 54 | 9.7% | 9.3% | 12.6% |
| Age 55 to 59 | 6.4% | 4.6% | 6.7% |
| Age 60 to 64 | 5.4% | 9.2% | 6.3% |
| Age 65 to 74 | 7.8% | 9.0% | 9.6% |
| Age 75 to 84 | 4.5% | 12.6% | 4.5% |
| Age 85 and over | 3.3% | 5.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Nashua, IA | Mountain City, TN | United States |
| White | 94.4% | 84.8% | 59.4% |
| Black | 0.9% | 3.8% | 12.2% |
| Asian | 0.0% | 1.0% | 5.6% |
| Native American | 0.0% | 0.7% | 0.6% |
| Hawaiian, Pacific Islander | 0.2% | 0.0% | 0.2% |
| Other | 0.5% | 0.0% | 0.4% |
| Two or More Races | 2.8% | 2.6% | 3.2% |
| Hispanic | 1.2% | 7.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Nashua, IA | Mountain City, TN | United States |
| Married Population | 55.7% | 42.5% | 49.8% |
| Currently Married | 55.0% | 39.1% | 48.0% |
| Married but Separated | 0.7% | 3.4% | 1.8% |
| Single Population | 44.3% | 57.5% | 50.2% |
| Never Married | 31.7% | 25.0% | 33.8% |
| Divorced | 7.3% | 20.2% | 10.8% |
| Widowed | 5.2% | 12.2% | 5.6% |
| space5 | | | |
| Household Size | 2.29 | 2.09 | 2.60 |
| Households | 656 | 1,022 | 124,010,992 |
| Family Households | 416 | 513 | 80,755,759 |
| Married couple, w/children | 28.1% | 18.9% | 30.5% |
| Married couple, no children | 48.6% | 46.2% | 42.9% |
| Non Family Households | 240 | 509 | 43,255,233 |
| Single householder, w/children | 19.5% | 24.6% | 15.8% |
| Single householder, no children | 3.8% | 10.3% | 10.8% |