| | Greencastle, PA | Camp Springs, MD | United States |
| Population | 4,199 | 22,903 | 329,725,481 |
| Female Population | 50.3% | 52.8% | 50.5% |
| Male Population | 49.7% | 47.2% | 49.5% |
| Median Age | 41.3 | 40.3 | 38.4 |
| space3 | | | |
| Population - 2010 | 3,987 | 18,770 | 309,327,143 |
| Population - 2000 | 3,722 | 17,968 | 285,036,114 |
| Population - 1990 | 3,600 | 16,392 | 251,960,433 |
| Pop. 2000 to Now | 7.2% | 17.6% | 15.6% |
| Pop. 1990 to Now | 10.8% | 28.9% | 30.8% |
| space4 | | | |
| Population Density | 2,644.2 | 2,982.2 | 93.4 |
| Land Area | 1.6 | 7.7 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Greencastle, PA | Camp Springs, MD | United States |
| Age 0 to 4 | 10.8% | 4.9% | 5.9% |
| Age 5 to 9 | 7.8% | 5.4% | 6.1% |
| Age 10 to 14 | 5.0% | 7.0% | 6.6% |
| Age 15 to 17 | 3.0% | 2.6% | 3.9% |
| Age 18 to 20 | 3.0% | 3.9% | 4.0% |
| Age 21 to 24 | 2.9% | 4.7% | 5.2% |
| Age 25 to 34 | 12.3% | 14.2% | 13.8% |
| Age 35 to 44 | 12.0% | 12.4% | 12.9% |
| Age 45 to 54 | 9.9% | 13.0% | 12.6% |
| Age 55 to 59 | 6.7% | 7.4% | 6.7% |
| Age 60 to 64 | 8.9% | 7.4% | 6.3% |
| Age 65 to 74 | 7.6% | 10.9% | 9.6% |
| Age 75 to 84 | 8.3% | 4.1% | 4.5% |
| Age 85 and over | 1.9% | 2.0% | 1.9% |
| space1 | | | |
| Race | | | |
| | Greencastle, PA | Camp Springs, MD | United States |
| White | 90.0% | 6.7% | 59.4% |
| Black | 1.8% | 77.9% | 12.2% |
| Asian | 1.4% | 1.8% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.3% | 0.4% |
| Two or More Races | 5.9% | 2.2% | 3.2% |
| Hispanic | 1.0% | 11.1% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Greencastle, PA | Camp Springs, MD | United States |
| Married Population | 58.8% | 45.8% | 49.8% |
| Currently Married | 58.2% | 43.0% | 48.0% |
| Married but Separated | 0.6% | 2.8% | 1.8% |
| Single Population | 41.2% | 54.2% | 50.2% |
| Never Married | 23.8% | 39.0% | 33.8% |
| Divorced | 9.8% | 10.6% | 10.8% |
| Widowed | 7.7% | 4.6% | 5.6% |
| space5 | | | |
| Household Size | 2.58 | 2.77 | 2.60 |
| Households | 1,623 | 8,260 | 124,010,992 |
| Family Households | 1,105 | 5,167 | 80,755,759 |
| Married couple, w/children | 27.9% | 28.9% | 30.5% |
| Married couple, no children | 47.8% | 40.1% | 42.9% |
| Non Family Households | 518 | 3,093 | 43,255,233 |
| Single householder, w/children | 14.0% | 15.5% | 15.8% |
| Single householder, no children | 10.3% | 15.5% | 10.8% |