| | St. Agatha, ME | Caribou, ME | United States |
| Population | 896 | 7,448 | 329,725,481 |
| Female Population | 52.9% | 46.3% | 50.5% |
| Male Population | 47.1% | 53.7% | 49.5% |
| Median Age | 59.3 | 52.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 746 | 8,167 | 309,327,143 |
| Population - 2000 | 802 | 8,312 | 285,036,114 |
| Population - 1990 | 919 | 9,415 | 251,960,433 |
| Pop. 2000 to Now | -11.1% | -8.3% | 15.6% |
| Pop. 1990 to Now | -22.4% | -19.0% | 30.8% |
| space4 | | | |
| Population Density | 30.4 | 93.9 | 93.4 |
| Land Area | 29.5 | 79.3 | 3,531,905.4 |
| Water Area | 5.5 | 0.8 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | St. Agatha, ME | Caribou, ME | United States |
| Age 0 to 4 | 2.7% | 5.5% | 5.9% |
| Age 5 to 9 | 2.3% | 3.6% | 6.1% |
| Age 10 to 14 | 5.1% | 3.2% | 6.6% |
| Age 15 to 17 | 2.1% | 2.5% | 3.9% |
| Age 18 to 20 | 1.1% | 3.6% | 4.0% |
| Age 21 to 24 | 1.7% | 5.5% | 5.2% |
| Age 25 to 34 | 5.1% | 10.8% | 13.8% |
| Age 35 to 44 | 6.7% | 8.6% | 12.9% |
| Age 45 to 54 | 16.1% | 12.5% | 12.6% |
| Age 55 to 59 | 11.2% | 11.9% | 6.7% |
| Age 60 to 64 | 14.6% | 6.9% | 6.3% |
| Age 65 to 74 | 20.2% | 14.0% | 9.6% |
| Age 75 to 84 | 8.8% | 6.0% | 4.5% |
| Age 85 and over | 2.2% | 5.5% | 1.9% |
| space1 | | | |
| Race | | | |
| | St. Agatha, ME | Caribou, ME | United States |
| White | 95.9% | 91.8% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.0% | 0.3% | 5.6% |
| Native American | 0.0% | 1.8% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.1% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.7% | 5.4% | 3.2% |
| Hispanic | 3.5% | 0.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | St. Agatha, ME | Caribou, ME | United States |
| Married Population | 62.6% | 50.4% | 49.8% |
| Currently Married | 61.2% | 48.9% | 48.0% |
| Married but Separated | 1.4% | 1.5% | 1.8% |
| Single Population | 37.4% | 49.6% | 50.2% |
| Never Married | 16.4% | 25.8% | 33.8% |
| Divorced | 7.6% | 15.3% | 10.8% |
| Widowed | 13.4% | 8.4% | 5.6% |
| space5 | | | |
| Household Size | 2.26 | 2.06 | 2.60 |
| Households | 396 | 3,540 | 124,010,992 |
| Family Households | 297 | 1,942 | 80,755,759 |
| Married couple, w/children | 20.9% | 18.3% | 30.5% |
| Married couple, no children | 60.6% | 58.5% | 42.9% |
| Non Family Households | 99 | 1,598 | 43,255,233 |
| Single householder, w/children | 5.1% | 13.0% | 15.8% |
| Single householder, no children | 13.5% | 10.1% | 10.8% |