| | Cornish, NH | Brandon, SD | United States |
| Population | 1,700 | 10,745 | 329,725,481 |
| Female Population | 50.9% | 49.4% | 50.5% |
| Male Population | 49.1% | 50.6% | 49.5% |
| Median Age | 55.8 | 36.5 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,639 | 8,962 | 309,327,143 |
| Population - 2000 | 1,661 | 5,693 | 285,036,114 |
| Population - 1990 | 1,659 | 3,824 | 251,960,433 |
| Pop. 2000 to Now | -2.7% | 78.6% | 15.6% |
| Pop. 1990 to Now | -2.6% | 165.9% | 30.8% |
| space4 | | | |
| Population Density | 40.4 | 1,997.2 | 93.4 |
| Land Area | 42.1 | 5.4 | 3,531,905.4 |
| Water Area | 0.7 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Cornish, NH | Brandon, SD | United States |
| Age 0 to 4 | 5.5% | 7.1% | 5.9% |
| Age 5 to 9 | 4.6% | 9.0% | 6.1% |
| Age 10 to 14 | 4.9% | 8.3% | 6.6% |
| Age 15 to 17 | 1.2% | 5.0% | 3.9% |
| Age 18 to 20 | 0.9% | 2.8% | 4.0% |
| Age 21 to 24 | 2.0% | 2.3% | 5.2% |
| Age 25 to 34 | 10.3% | 11.6% | 13.8% |
| Age 35 to 44 | 8.2% | 17.8% | 12.9% |
| Age 45 to 54 | 11.9% | 13.0% | 12.6% |
| Age 55 to 59 | 6.8% | 6.3% | 6.7% |
| Age 60 to 64 | 14.0% | 6.3% | 6.3% |
| Age 65 to 74 | 19.2% | 7.1% | 9.6% |
| Age 75 to 84 | 8.5% | 1.6% | 4.5% |
| Age 85 and over | 1.9% | 1.8% | 1.9% |
| space1 | | | |
| Race | | | |
| | Cornish, NH | Brandon, SD | United States |
| White | 90.6% | 92.9% | 59.4% |
| Black | 0.0% | 2.2% | 12.2% |
| Asian | 0.6% | 0.4% | 5.6% |
| Native American | 0.0% | 0.3% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.2% | 0.2% |
| Other | 6.6% | 0.0% | 0.4% |
| Two or More Races | 2.1% | 1.3% | 3.2% |
| Hispanic | 0.1% | 2.8% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Cornish, NH | Brandon, SD | United States |
| Married Population | 56.5% | 63.0% | 49.8% |
| Currently Married | 55.6% | 62.7% | 48.0% |
| Married but Separated | 1.0% | 0.4% | 1.8% |
| Single Population | 43.5% | 37.0% | 50.2% |
| Never Married | 24.8% | 22.5% | 33.8% |
| Divorced | 9.5% | 11.7% | 10.8% |
| Widowed | 9.2% | 2.8% | 5.6% |
| space5 | | | |
| Household Size | 2.31 | 2.76 | 2.60 |
| Households | 735 | 3,899 | 124,010,992 |
| Family Households | 407 | 2,864 | 80,755,759 |
| Married couple, w/children | 23.1% | 43.9% | 30.5% |
| Married couple, no children | 65.8% | 41.4% | 42.9% |
| Non Family Households | 328 | 1,035 | 43,255,233 |
| Single householder, w/children | 6.1% | 10.2% | 15.8% |
| Single householder, no children | 4.9% | 4.5% | 10.8% |