| | Preston, MD | Cambridge, MD | United States |
| Population | 951 | 13,026 | 329,725,481 |
| Female Population | 53.5% | 52.2% | 50.5% |
| Male Population | 46.5% | 47.8% | 49.5% |
| Median Age | 34.3 | 38.2 | 38.4 |
| space3 | | | |
| Population - 2010 | 721 | 12,456 | 309,327,143 |
| Population - 2000 | 566 | 10,911 | 285,036,114 |
| Population - 1990 | 437 | 11,514 | 251,960,433 |
| Pop. 2000 to Now | 23.7% | 11.9% | 15.6% |
| Pop. 1990 to Now | 60.2% | 6.1% | 30.8% |
| space4 | | | |
| Population Density | 1,757.9 | 1,223.1 | 93.4 |
| Land Area | 0.5 | 10.7 | 3,531,905.4 |
| Water Area | 0.0 | 2.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Preston, MD | Cambridge, MD | United States |
| Age 0 to 4 | 11.8% | 7.2% | 5.9% |
| Age 5 to 9 | 10.0% | 6.1% | 6.1% |
| Age 10 to 14 | 9.3% | 5.2% | 6.6% |
| Age 15 to 17 | 4.0% | 5.1% | 3.9% |
| Age 18 to 20 | 0.5% | 3.5% | 4.0% |
| Age 21 to 24 | 2.3% | 3.8% | 5.2% |
| Age 25 to 34 | 13.5% | 15.4% | 13.8% |
| Age 35 to 44 | 23.1% | 12.0% | 12.9% |
| Age 45 to 54 | 6.7% | 10.9% | 12.6% |
| Age 55 to 59 | 5.8% | 5.6% | 6.7% |
| Age 60 to 64 | 3.6% | 5.6% | 6.3% |
| Age 65 to 74 | 4.7% | 11.6% | 9.6% |
| Age 75 to 84 | 3.0% | 6.6% | 4.5% |
| Age 85 and over | 1.7% | 1.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Preston, MD | Cambridge, MD | United States |
| White | 89.4% | 39.8% | 59.4% |
| Black | 5.2% | 42.8% | 12.2% |
| Asian | 0.0% | 2.2% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.8% | 0.3% | 0.4% |
| Two or More Races | 1.8% | 7.9% | 3.2% |
| Hispanic | 2.8% | 7.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Preston, MD | Cambridge, MD | United States |
| Married Population | 52.0% | 37.1% | 49.8% |
| Currently Married | 50.5% | 34.7% | 48.0% |
| Married but Separated | 1.5% | 2.4% | 1.8% |
| Single Population | 48.0% | 62.9% | 50.2% |
| Never Married | 23.2% | 41.3% | 33.8% |
| Divorced | 15.4% | 14.3% | 10.8% |
| Widowed | 9.5% | 7.3% | 5.6% |
| space5 | | | |
| Household Size | 2.86 | 2.32 | 2.60 |
| Households | 333 | 5,413 | 124,010,992 |
| Family Households | 244 | 2,967 | 80,755,759 |
| Married couple, w/children | 52.5% | 16.9% | 30.5% |
| Married couple, no children | 14.3% | 36.4% | 42.9% |
| Non Family Households | 89 | 2,446 | 43,255,233 |
| Single householder, w/children | 28.3% | 34.8% | 15.8% |
| Single householder, no children | 4.9% | 11.9% | 10.8% |