| | Carthage, TX | Texarkana, AR | United States |
| Population | 6,510 | 29,492 | 329,725,481 |
| Female Population | 52.7% | 51.7% | 50.5% |
| Male Population | 47.3% | 48.4% | 49.5% |
| Median Age | 36.6 | 40.4 | 38.4 |
| space3 | | | |
| Population - 2010 | 6,765 | 29,965 | 309,327,143 |
| Population - 2000 | 6,664 | 26,448 | 285,036,114 |
| Population - 1990 | 6,496 | 22,631 | 251,960,433 |
| Pop. 2000 to Now | -4.7% | 11.8% | 15.6% |
| Pop. 1990 to Now | -2.2% | 30.6% | 30.8% |
| space4 | | | |
| Population Density | 610.7 | 704.1 | 93.4 |
| Land Area | 10.7 | 41.9 | 3,531,905.4 |
| Water Area | 0.0 | 0.2 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Carthage, TX | Texarkana, AR | United States |
| Age 0 to 4 | 7.4% | 6.0% | 5.9% |
| Age 5 to 9 | 8.3% | 6.9% | 6.1% |
| Age 10 to 14 | 6.2% | 6.3% | 6.6% |
| Age 15 to 17 | 1.8% | 3.8% | 3.9% |
| Age 18 to 20 | 5.5% | 4.2% | 4.0% |
| Age 21 to 24 | 7.7% | 3.9% | 5.2% |
| Age 25 to 34 | 10.3% | 14.2% | 13.8% |
| Age 35 to 44 | 8.5% | 12.2% | 12.9% |
| Age 45 to 54 | 11.9% | 12.9% | 12.6% |
| Age 55 to 59 | 3.0% | 7.1% | 6.7% |
| Age 60 to 64 | 13.3% | 5.8% | 6.3% |
| Age 65 to 74 | 8.6% | 10.0% | 9.6% |
| Age 75 to 84 | 6.3% | 5.2% | 4.5% |
| Age 85 and over | 1.2% | 1.4% | 1.9% |
| space1 | | | |
| Race | | | |
| | Carthage, TX | Texarkana, AR | United States |
| White | 67.2% | 56.5% | 59.4% |
| Black | 12.5% | 35.0% | 12.2% |
| Asian | 2.0% | 0.1% | 5.6% |
| Native American | 0.0% | 1.2% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.4% | 0.4% |
| Two or More Races | 3.3% | 2.3% | 3.2% |
| Hispanic | 15.1% | 4.5% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Carthage, TX | Texarkana, AR | United States |
| Married Population | 49.4% | 43.6% | 49.8% |
| Currently Married | 48.9% | 39.9% | 48.0% |
| Married but Separated | 0.5% | 3.6% | 1.8% |
| Single Population | 50.6% | 56.4% | 50.2% |
| Never Married | 26.8% | 33.4% | 33.8% |
| Divorced | 17.1% | 15.7% | 10.8% |
| Widowed | 6.7% | 7.4% | 5.6% |
| space5 | | | |
| Household Size | 2.46 | 2.48 | 2.60 |
| Households | 2,496 | 11,381 | 124,010,992 |
| Family Households | 1,669 | 7,204 | 80,755,759 |
| Married couple, w/children | 26.2% | 18.5% | 30.5% |
| Married couple, no children | 40.4% | 40.7% | 42.9% |
| Non Family Households | 827 | 4,177 | 43,255,233 |
| Single householder, w/children | 24.9% | 27.9% | 15.8% |
| Single householder, no children | 8.4% | 13.0% | 10.8% |