| | Monterey, TN | Unionville, TN | United States |
| Population | 2,746 | 2,151 | 329,725,481 |
| Female Population | 46.8% | 55.8% | 50.5% |
| Male Population | 53.2% | 44.2% | 49.5% |
| Median Age | 27.4 | 42.7 | 38.4 |
| space3 | | | |
| Population - 2010 | 2,829 | 1,016 | 309,327,143 |
| Population - 2000 | 2,717 | 1,064 | 285,036,114 |
| Population - 1990 | 2,559 | 648 | 251,960,433 |
| Pop. 2000 to Now | 6.3% | 61.4% | 15.6% |
| Pop. 1990 to Now | 12.9% | 165.0% | 30.8% |
| space4 | | | |
| Population Density | 906.9 | 238.2 | 93.4 |
| Land Area | 3.0 | 9.0 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Monterey, TN | Unionville, TN | United States |
| Age 0 to 4 | 9.4% | 6.2% | 5.9% |
| Age 5 to 9 | 7.5% | 0.8% | 6.1% |
| Age 10 to 14 | 9.0% | 10.0% | 6.6% |
| Age 15 to 17 | 14.7% | 11.1% | 3.9% |
| Age 18 to 20 | 0.9% | 2.5% | 4.0% |
| Age 21 to 24 | 3.6% | 3.6% | 5.2% |
| Age 25 to 34 | 14.6% | 8.2% | 13.8% |
| Age 35 to 44 | 9.7% | 13.0% | 12.9% |
| Age 45 to 54 | 9.3% | 21.0% | 12.6% |
| Age 55 to 59 | 4.9% | 2.1% | 6.7% |
| Age 60 to 64 | 4.0% | 6.6% | 6.3% |
| Age 65 to 74 | 6.8% | 11.2% | 9.6% |
| Age 75 to 84 | 3.7% | 1.0% | 4.5% |
| Age 85 and over | 2.0% | 2.7% | 1.9% |
| space1 | | | |
| Race | | | |
| | Monterey, TN | Unionville, TN | United States |
| White | 74.5% | 96.9% | 59.4% |
| Black | 0.1% | 1.2% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 0.5% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.7% | 1.9% | 3.2% |
| Hispanic | 24.1% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Monterey, TN | Unionville, TN | United States |
| Married Population | 52.8% | 44.7% | 49.8% |
| Currently Married | 50.1% | 42.9% | 48.0% |
| Married but Separated | 2.8% | 1.7% | 1.8% |
| Single Population | 47.2% | 55.4% | 50.2% |
| Never Married | 24.5% | 25.0% | 33.8% |
| Divorced | 14.0% | 20.1% | 10.8% |
| Widowed | 8.6% | 10.2% | 5.6% |
| space5 | | | |
| Household Size | 3.17 | 3.23 | 2.60 |
| Households | 839 | 666 | 124,010,992 |
| Family Households | 600 | 587 | 80,755,759 |
| Married couple, w/children | 41.5% | 34.8% | 30.5% |
| Married couple, no children | 19.3% | 26.2% | 42.9% |
| Non Family Households | 239 | 79 | 43,255,233 |
| Single householder, w/children | 30.3% | 18.4% | 15.8% |
| Single householder, no children | 8.8% | 20.6% | 10.8% |