| | Fountain City, WI | Buffalo City, WI | United States |
| Population | 788 | 801 | 329,725,481 |
| Female Population | 52.5% | 45.6% | 50.5% |
| Male Population | 47.5% | 54.4% | 49.5% |
| Median Age | 42.5 | 55.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 836 | 1,017 | 309,327,143 |
| Population - 2000 | 983 | 1,040 | 285,036,114 |
| Population - 1990 | 938 | 989 | 251,960,433 |
| Pop. 2000 to Now | -14.3% | -8.9% | 15.6% |
| Pop. 1990 to Now | -10.2% | -4.2% | 30.8% |
| space4 | | | |
| Population Density | 178.2 | 379.4 | 93.4 |
| Land Area | 4.4 | 2.1 | 3,531,905.4 |
| Water Area | 1.2 | 3.9 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Fountain City, WI | Buffalo City, WI | United States |
| Age 0 to 4 | 4.9% | 4.9% | 5.9% |
| Age 5 to 9 | 4.4% | 3.5% | 6.1% |
| Age 10 to 14 | 6.2% | 2.1% | 6.6% |
| Age 15 to 17 | 2.7% | 1.5% | 3.9% |
| Age 18 to 20 | 4.2% | 1.5% | 4.0% |
| Age 21 to 24 | 7.9% | 1.0% | 5.2% |
| Age 25 to 34 | 13.2% | 14.4% | 13.8% |
| Age 35 to 44 | 8.9% | 9.5% | 12.9% |
| Age 45 to 54 | 16.5% | 11.1% | 12.6% |
| Age 55 to 59 | 6.0% | 9.2% | 6.7% |
| Age 60 to 64 | 5.3% | 14.5% | 6.3% |
| Age 65 to 74 | 11.8% | 17.2% | 9.6% |
| Age 75 to 84 | 7.2% | 7.7% | 4.5% |
| Age 85 and over | 0.8% | 1.9% | 1.9% |
| space1 | | | |
| Race | | | |
| | Fountain City, WI | Buffalo City, WI | United States |
| White | 91.9% | 97.0% | 59.4% |
| Black | 2.8% | 1.7% | 12.2% |
| Asian | 0.0% | 0.0% | 5.6% |
| Native American | 2.4% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 2.7% | 1.2% | 3.2% |
| Hispanic | 0.3% | 0.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Fountain City, WI | Buffalo City, WI | United States |
| Married Population | 41.2% | 64.4% | 49.8% |
| Currently Married | 38.3% | 64.0% | 48.0% |
| Married but Separated | 2.9% | 0.4% | 1.8% |
| Single Population | 58.8% | 35.6% | 50.2% |
| Never Married | 36.7% | 20.8% | 33.8% |
| Divorced | 11.7% | 11.4% | 10.8% |
| Widowed | 10.4% | 3.3% | 5.6% |
| space5 | | | |
| Household Size | 2.28 | 2.05 | 2.60 |
| Households | 345 | 390 | 124,010,992 |
| Family Households | 151 | 262 | 80,755,759 |
| Married couple, w/children | 25.2% | 14.5% | 30.5% |
| Married couple, no children | 47.0% | 72.9% | 42.9% |
| Non Family Households | 194 | 128 | 43,255,233 |
| Single householder, w/children | 19.9% | 5.3% | 15.8% |
| Single householder, no children | 7.9% | 7.3% | 10.8% |