| | Accident, MD | Chicopee, MA | United States |
| Population | 342 | 55,636 | 329,725,481 |
| Female Population | 48.5% | 50.6% | 50.5% |
| Male Population | 51.5% | 49.4% | 49.5% |
| Median Age | 33.2 | 41.1 | 38.4 |
| space3 | | | |
| Population - 2010 | 325 | 55,306 | 309,327,143 |
| Population - 2000 | 353 | 54,653 | 285,036,114 |
| Population - 1990 | 349 | 56,632 | 251,960,433 |
| Pop. 2000 to Now | -11.9% | 0.3% | 15.6% |
| Pop. 1990 to Now | -10.9% | -3.2% | 30.8% |
| space4 | | | |
| Population Density | 692.3 | 2,429.1 | 93.4 |
| Land Area | 0.5 | 22.9 | 3,531,905.4 |
| Water Area | 0.0 | 1.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Accident, MD | Chicopee, MA | United States |
| Age 0 to 4 | 9.4% | 4.8% | 5.9% |
| Age 5 to 9 | 8.2% | 4.9% | 6.1% |
| Age 10 to 14 | 4.7% | 5.9% | 6.6% |
| Age 15 to 17 | 4.4% | 4.1% | 3.9% |
| Age 18 to 20 | 1.8% | 4.5% | 4.0% |
| Age 21 to 24 | 7.3% | 5.0% | 5.2% |
| Age 25 to 34 | 18.4% | 13.2% | 13.8% |
| Age 35 to 44 | 13.2% | 12.2% | 12.9% |
| Age 45 to 54 | 7.3% | 11.5% | 12.6% |
| Age 55 to 59 | 8.2% | 7.4% | 6.7% |
| Age 60 to 64 | 4.1% | 7.5% | 6.3% |
| Age 65 to 74 | 6.7% | 11.4% | 9.6% |
| Age 75 to 84 | 3.5% | 5.2% | 4.5% |
| Age 85 and over | 2.9% | 2.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Accident, MD | Chicopee, MA | United States |
| White | 91.8% | 69.4% | 59.4% |
| Black | 0.3% | 4.7% | 12.2% |
| Asian | 0.3% | 1.7% | 5.6% |
| Native American | 0.3% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 1.8% | 1.6% | 3.2% |
| Hispanic | 5.6% | 22.4% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Accident, MD | Chicopee, MA | United States |
| Married Population | 53.4% | 40.1% | 49.8% |
| Currently Married | 51.1% | 38.7% | 48.0% |
| Married but Separated | 2.3% | 1.4% | 1.8% |
| Single Population | 46.6% | 59.9% | 50.2% |
| Never Married | 28.9% | 39.5% | 33.8% |
| Divorced | 12.4% | 13.2% | 10.8% |
| Widowed | 5.3% | 7.2% | 5.6% |
| space5 | | | |
| Household Size | 2.04 | 2.29 | 2.60 |
| Households | 168 | 23,852 | 124,010,992 |
| Family Households | 97 | 14,155 | 80,755,759 |
| Married couple, w/children | 43.3% | 20.6% | 30.5% |
| Married couple, no children | 29.9% | 39.9% | 42.9% |
| Non Family Households | 71 | 9,697 | 43,255,233 |
| Single householder, w/children | 19.6% | 22.9% | 15.8% |
| Single householder, no children | 7.2% | 16.6% | 10.8% |