| | Union City, NJ | Elmira, NY | United States |
| Population | 67,903 | 26,737 | 329,725,481 |
| Female Population | 51.1% | 50.1% | 50.5% |
| Male Population | 48.9% | 49.9% | 49.5% |
| Median Age | 36.7 | 35.8 | 38.4 |
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| Population - 2010 | 66,458 | 29,258 | 309,327,143 |
| Population - 2000 | 67,088 | 30,940 | 285,036,114 |
| Population - 1990 | 58,012 | 33,724 | 251,960,433 |
| Pop. 2000 to Now | 0.1% | -12.6% | 15.6% |
| Pop. 1990 to Now | 15.7% | -19.8% | 30.8% |
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| Population Density | 52,760.7 | 3,686.9 | 93.4 |
| Land Area | 1.3 | 7.3 | 3,531,905.4 |
| Water Area | 0.0 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Union City, NJ | Elmira, NY | United States |
| Age 0 to 4 | 6.1% | 4.7% | 5.9% |
| Age 5 to 9 | 6.0% | 6.5% | 6.1% |
| Age 10 to 14 | 5.9% | 7.8% | 6.6% |
| Age 15 to 17 | 4.4% | 3.4% | 3.9% |
| Age 18 to 20 | 4.7% | 5.4% | 4.0% |
| Age 21 to 24 | 6.1% | 5.0% | 5.2% |
| Age 25 to 34 | 14.4% | 16.0% | 13.8% |
| Age 35 to 44 | 15.6% | 13.1% | 12.9% |
| Age 45 to 54 | 14.5% | 11.4% | 12.6% |
| Age 55 to 59 | 6.2% | 7.1% | 6.7% |
| Age 60 to 64 | 4.3% | 5.4% | 6.3% |
| Age 65 to 74 | 6.3% | 9.2% | 9.6% |
| Age 75 to 84 | 4.0% | 2.8% | 4.5% |
| Age 85 and over | 1.4% | 2.1% | 1.9% |
| space1 | | | |
| Race | | | |
| | Union City, NJ | Elmira, NY | United States |
| White | 13.9% | 74.9% | 59.4% |
| Black | 2.1% | 11.7% | 12.2% |
| Asian | 2.9% | 1.0% | 5.6% |
| Native American | 0.0% | 0.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.2% | 0.6% | 0.4% |
| Two or More Races | 0.9% | 6.0% | 3.2% |
| Hispanic | 79.9% | 5.6% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Union City, NJ | Elmira, NY | United States |
| Married Population | 42.2% | 37.2% | 49.8% |
| Currently Married | 38.3% | 33.9% | 48.0% |
| Married but Separated | 3.9% | 3.3% | 1.8% |
| Single Population | 57.8% | 62.8% | 50.2% |
| Never Married | 43.3% | 44.5% | 33.8% |
| Divorced | 9.8% | 13.1% | 10.8% |
| Widowed | 4.7% | 5.1% | 5.6% |
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| Household Size | 2.67 | 2.36 | 2.60 |
| Households | 25,292 | 9,871 | 124,010,992 |
| Family Households | 16,764 | 5,603 | 80,755,759 |
| Married couple, w/children | 29.0% | 24.8% | 30.5% |
| Married couple, no children | 26.1% | 33.0% | 42.9% |
| Non Family Households | 8,528 | 4,268 | 43,255,233 |
| Single householder, w/children | 24.2% | 29.6% | 15.8% |
| Single householder, no children | 20.7% | 12.6% | 10.8% |