| | Pittsburg, TX | Clarksville, TX | United States |
| Population | 4,351 | 2,862 | 329,725,481 |
| Female Population | 53.9% | 54.8% | 50.5% |
| Male Population | 46.1% | 45.2% | 49.5% |
| Median Age | 33.4 | 49.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 4,522 | 3,352 | 309,327,143 |
| Population - 2000 | 4,347 | 3,883 | 285,036,114 |
| Population - 1990 | 4,007 | 4,311 | 251,960,433 |
| Pop. 2000 to Now | 7.7% | -21.4% | 15.6% |
| Pop. 1990 to Now | 16.8% | -29.2% | 30.8% |
| space4 | | | |
| Population Density | 1,209.6 | 935.0 | 93.4 |
| Land Area | 3.6 | 3.1 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Pittsburg, TX | Clarksville, TX | United States |
| Age 0 to 4 | 8.9% | 7.5% | 5.9% |
| Age 5 to 9 | 11.2% | 0.3% | 6.1% |
| Age 10 to 14 | 7.2% | 6.8% | 6.6% |
| Age 15 to 17 | 3.2% | 2.2% | 3.9% |
| Age 18 to 20 | 1.5% | 0.9% | 4.0% |
| Age 21 to 24 | 5.5% | 2.5% | 5.2% |
| Age 25 to 34 | 15.8% | 6.9% | 13.8% |
| Age 35 to 44 | 11.1% | 17.1% | 12.9% |
| Age 45 to 54 | 13.5% | 18.2% | 12.6% |
| Age 55 to 59 | 4.1% | 7.6% | 6.7% |
| Age 60 to 64 | 5.3% | 7.0% | 6.3% |
| Age 65 to 74 | 6.9% | 13.2% | 9.6% |
| Age 75 to 84 | 3.8% | 8.1% | 4.5% |
| Age 85 and over | 2.0% | 1.6% | 1.9% |
| space1 | | | |
| Race | | | |
| | Pittsburg, TX | Clarksville, TX | United States |
| White | 34.4% | 49.8% | 59.4% |
| Black | 27.5% | 40.5% | 12.2% |
| Asian | 1.4% | 0.0% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 0.0% | 0.0% | 0.2% |
| Other | 0.3% | 0.4% | 0.4% |
| Two or More Races | 4.1% | 6.1% | 3.2% |
| Hispanic | 32.2% | 3.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Pittsburg, TX | Clarksville, TX | United States |
| Married Population | 42.1% | 42.6% | 49.8% |
| Currently Married | 38.4% | 39.8% | 48.0% |
| Married but Separated | 3.8% | 2.8% | 1.8% |
| Single Population | 57.9% | 57.4% | 50.2% |
| Never Married | 35.0% | 26.8% | 33.8% |
| Divorced | 12.0% | 18.3% | 10.8% |
| Widowed | 10.8% | 12.3% | 5.6% |
| space5 | | | |
| Household Size | 2.62 | 2.39 | 2.60 |
| Households | 1,646 | 1,128 | 124,010,992 |
| Family Households | 925 | 719 | 80,755,759 |
| Married couple, w/children | 27.5% | 15.2% | 30.5% |
| Married couple, no children | 32.1% | 50.6% | 42.9% |
| Non Family Households | 721 | 409 | 43,255,233 |
| Single householder, w/children | 32.6% | 16.0% | 15.8% |
| Single householder, no children | 7.8% | 18.2% | 10.8% |