| | Lansdowne, MD | Dundalk, MD | United States |
| Population | 9,310 | 66,426 | 329,725,481 |
| Female Population | 52.3% | 51.8% | 50.5% |
| Male Population | 47.7% | 48.2% | 49.5% |
| Median Age | 37 | 37.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 8,629 | 62,444 | 309,327,143 |
| Population - 2000 | 8,690 | 62,306 | 285,036,114 |
| Population - 1990 | 8,384 | 65,800 | 251,960,433 |
| Pop. 2000 to Now | -4.5% | 0.1% | 15.6% |
| Pop. 1990 to Now | -1.1% | -5.2% | 30.8% |
| space4 | | | |
| Population Density | 4,090.5 | 5,083.1 | 93.4 |
| Land Area | 2.3 | 13.1 | 3,531,905.4 |
| Water Area | 0.1 | 4.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Lansdowne, MD | Dundalk, MD | United States |
| Age 0 to 4 | 10.0% | 6.3% | 5.9% |
| Age 5 to 9 | 7.3% | 7.0% | 6.1% |
| Age 10 to 14 | 6.4% | 6.9% | 6.6% |
| Age 15 to 17 | 2.3% | 3.7% | 3.9% |
| Age 18 to 20 | 2.5% | 3.4% | 4.0% |
| Age 21 to 24 | 3.9% | 4.7% | 5.2% |
| Age 25 to 34 | 14.4% | 14.5% | 13.8% |
| Age 35 to 44 | 16.6% | 13.3% | 12.9% |
| Age 45 to 54 | 8.6% | 12.1% | 12.6% |
| Age 55 to 59 | 7.1% | 5.8% | 6.7% |
| Age 60 to 64 | 8.0% | 7.2% | 6.3% |
| Age 65 to 74 | 8.2% | 8.8% | 9.6% |
| Age 75 to 84 | 3.3% | 4.6% | 4.5% |
| Age 85 and over | 1.4% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Lansdowne, MD | Dundalk, MD | United States |
| White | 53.8% | 66.0% | 59.4% |
| Black | 24.6% | 15.5% | 12.2% |
| Asian | 0.9% | 3.0% | 5.6% |
| Native American | 0.0% | 0.6% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.4% | 0.4% | 0.4% |
| Two or More Races | 6.0% | 3.5% | 3.2% |
| Hispanic | 14.3% | 11.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Lansdowne, MD | Dundalk, MD | United States |
| Married Population | 40.0% | 41.5% | 49.8% |
| Currently Married | 38.0% | 38.9% | 48.0% |
| Married but Separated | 2.0% | 2.7% | 1.8% |
| Single Population | 60.0% | 58.5% | 50.2% |
| Never Married | 42.8% | 39.3% | 33.8% |
| Divorced | 11.9% | 10.9% | 10.8% |
| Widowed | 5.4% | 8.2% | 5.6% |
| space5 | | | |
| Household Size | 2.61 | 2.67 | 2.60 |
| Households | 3,572 | 24,753 | 124,010,992 |
| Family Households | 2,258 | 16,087 | 80,755,759 |
| Married couple, w/children | 26.7% | 24.5% | 30.5% |
| Married couple, no children | 26.1% | 34.2% | 42.9% |
| Non Family Households | 1,314 | 8,666 | 43,255,233 |
| Single householder, w/children | 30.0% | 25.2% | 15.8% |
| Single householder, no children | 17.1% | 16.1% | 10.8% |