| | Columbia, VA | Reading, PA | United States |
| Population | 56 | 94,161 | 329,725,481 |
| Female Population | 41.1% | 51.8% | 50.5% |
| Male Population | 58.9% | 48.2% | 49.5% |
| Median Age | 64.5 | 30.8 | 38.4 |
| space3 | | | |
| Population - 2010 | 83 | 88,045 | 309,327,143 |
| Population - 2000 | 49 | 81,207 | 285,036,114 |
| Population - 1990 | 58 | 78,380 | 251,960,433 |
| Pop. 2000 to Now | 67.4% | 8.6% | 15.6% |
| Pop. 1990 to Now | 41.4% | 12.6% | 30.8% |
| space4 | | | |
| Population Density | 391.6 | 9,586.7 | 93.4 |
| Land Area | 0.1 | 9.8 | 3,531,905.4 |
| Water Area | 0.0 | 0.3 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Columbia, VA | Reading, PA | United States |
| Age 0 to 4 | 0.0% | 8.0% | 5.9% |
| Age 5 to 9 | 0.0% | 8.4% | 6.1% |
| Age 10 to 14 | 0.0% | 8.0% | 6.6% |
| Age 15 to 17 | 0.0% | 4.8% | 3.9% |
| Age 18 to 20 | 0.0% | 5.2% | 4.0% |
| Age 21 to 24 | 0.0% | 6.9% | 5.2% |
| Age 25 to 34 | 0.0% | 14.6% | 13.8% |
| Age 35 to 44 | 37.5% | 11.6% | 12.9% |
| Age 45 to 54 | 10.7% | 11.5% | 12.6% |
| Age 55 to 59 | 0.0% | 5.8% | 6.7% |
| Age 60 to 64 | 1.8% | 4.7% | 6.3% |
| Age 65 to 74 | 46.4% | 6.4% | 9.6% |
| Age 75 to 84 | 3.6% | 2.9% | 4.5% |
| Age 85 and over | 0.0% | 1.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Columbia, VA | Reading, PA | United States |
| White | 91.1% | 21.4% | 59.4% |
| Black | 8.9% | 8.7% | 12.2% |
| Asian | 0.0% | 0.9% | 5.6% |
| Native American | 0.0% | 0.1% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 0.0% | 2.0% | 3.2% |
| Hispanic | 0.0% | 66.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Columbia, VA | Reading, PA | United States |
| Married Population | 48.2% | 34.4% | 49.8% |
| Currently Married | 48.2% | 30.1% | 48.0% |
| Married but Separated | 0.0% | 4.3% | 1.8% |
| Single Population | 51.8% | 65.6% | 50.2% |
| Never Married | 42.9% | 48.4% | 33.8% |
| Divorced | 5.4% | 12.5% | 10.8% |
| Widowed | 3.6% | 4.6% | 5.6% |
| space5 | | | |
| Household Size | 3.29 | 2.82 | 2.60 |
| Households | 17 | 32,380 | 124,010,992 |
| Family Households | 14 | 20,178 | 80,755,759 |
| Married couple, w/children | 0.0% | 21.2% | 30.5% |
| Married couple, no children | 85.7% | 24.0% | 42.9% |
| Non Family Households | 3 | 12,202 | 43,255,233 |
| Single householder, w/children | 0.0% | 37.4% | 15.8% |
| Single householder, no children | 14.3% | 17.4% | 10.8% |