| | Harrisburg, OR | Trafford, PA | United States |
| Population | 3,645 | 3,291 | 329,725,481 |
| Female Population | 50.7% | 53.9% | 50.5% |
| Male Population | 49.3% | 46.1% | 49.5% |
| Median Age | 35.8 | 38.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,573 | 3,228 | 309,327,143 |
| Population - 2000 | 2,795 | 3,236 | 285,036,114 |
| Population - 1990 | 1,939 | 3,345 | 251,960,433 |
| Pop. 2000 to Now | 40.1% | -6.8% | 15.6% |
| Pop. 1990 to Now | 102.0% | -9.9% | 30.8% |
| space4 | | | |
| Population Density | 2,612.9 | 2,269.7 | 93.4 |
| Land Area | 1.4 | 1.5 | 3,531,905.4 |
| Water Area | 0.1 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Harrisburg, OR | Trafford, PA | United States |
| Age 0 to 4 | 9.0% | 6.2% | 5.9% |
| Age 5 to 9 | 11.4% | 8.0% | 6.1% |
| Age 10 to 14 | 7.4% | 4.7% | 6.6% |
| Age 15 to 17 | 3.3% | 2.1% | 3.9% |
| Age 18 to 20 | 0.5% | 1.9% | 4.0% |
| Age 21 to 24 | 2.5% | 1.1% | 5.2% |
| Age 25 to 34 | 15.3% | 20.5% | 13.8% |
| Age 35 to 44 | 19.8% | 9.8% | 12.9% |
| Age 45 to 54 | 7.1% | 9.4% | 12.6% |
| Age 55 to 59 | 3.7% | 12.8% | 6.7% |
| Age 60 to 64 | 10.8% | 5.8% | 6.3% |
| Age 65 to 74 | 5.7% | 8.6% | 9.6% |
| Age 75 to 84 | 1.9% | 4.9% | 4.5% |
| Age 85 and over | 1.7% | 4.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Harrisburg, OR | Trafford, PA | United States |
| White | 89.5% | 93.4% | 59.4% |
| Black | 0.3% | 0.2% | 12.2% |
| Asian | 0.0% | 3.3% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.5% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 8.9% | 2.0% | 3.2% |
| Hispanic | 1.2% | 0.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Harrisburg, OR | Trafford, PA | United States |
| Married Population | 56.6% | 48.1% | 49.8% |
| Currently Married | 53.8% | 45.1% | 48.0% |
| Married but Separated | 2.8% | 2.9% | 1.8% |
| Single Population | 43.4% | 51.9% | 50.2% |
| Never Married | 23.3% | 27.8% | 33.8% |
| Divorced | 16.2% | 15.1% | 10.8% |
| Widowed | 4.0% | 9.1% | 5.6% |
| space5 | | | |
| Household Size | 2.66 | 2.30 | 2.60 |
| Households | 1,369 | 1,432 | 124,010,992 |
| Family Households | 937 | 862 | 80,755,759 |
| Married couple, w/children | 43.0% | 31.1% | 30.5% |
| Married couple, no children | 24.3% | 33.4% | 42.9% |
| Non Family Households | 432 | 570 | 43,255,233 |
| Single householder, w/children | 23.4% | 16.9% | 15.8% |
| Single householder, no children | 9.3% | 18.6% | 10.8% |