| | Matagorda, TX | Lamar, TX | United States |
| Population | 431 | 1,328 | 329,725,481 |
| Female Population | 42.5% | 63.5% | 50.5% |
| Male Population | 57.5% | 36.5% | 49.5% |
| Median Age | 62.3 | 28.9 | 38.4 |
| space3 | | | |
| Population - 2010 | 525 | 583 | 309,327,143 |
| Population - 2000 | 479 | 663 | 285,036,114 |
| Population - 1990 | 418 | 398 | 251,960,433 |
| Pop. 2000 to Now | -7.3% | -8.1% | 15.6% |
| Pop. 1990 to Now | 6.2% | 53.0% | 30.8% |
| space4 | | | |
| Population Density | 233.9 | 433.9 | 93.4 |
| Land Area | 1.8 | 3.1 | 3,531,905.4 |
| Water Area | 0.2 | 1.8 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Matagorda, TX | Lamar, TX | United States |
| Age 0 to 4 | 0.0% | 14.2% | 5.9% |
| Age 5 to 9 | 0.0% | 10.4% | 6.1% |
| Age 10 to 14 | 8.4% | 8.8% | 6.6% |
| Age 15 to 17 | 0.0% | 0.0% | 3.9% |
| Age 18 to 20 | 0.0% | 2.0% | 4.0% |
| Age 21 to 24 | 5.6% | 0.0% | 5.2% |
| Age 25 to 34 | 6.5% | 15.5% | 13.8% |
| Age 35 to 44 | 4.2% | 1.6% | 12.9% |
| Age 45 to 54 | 17.9% | 11.5% | 12.6% |
| Age 55 to 59 | 5.1% | 0.0% | 6.7% |
| Age 60 to 64 | 27.1% | 10.2% | 6.3% |
| Age 65 to 74 | 15.5% | 5.5% | 9.6% |
| Age 75 to 84 | 9.7% | 15.1% | 4.5% |
| Age 85 and over | 0.0% | 5.3% | 1.9% |
| space1 | | | |
| Race | | | |
| | Matagorda, TX | Lamar, TX | United States |
| White | 81.2% | 95.7% | 59.4% |
| Black | 0.0% | 0.0% | 12.2% |
| Asian | 0.0% | 0.1% | 5.6% |
| Native American | 0.0% | 2.2% | 0.6% |
| Hawaiian, Pacific Islander | 1.9% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 0.0% | 0.0% | 3.2% |
| Hispanic | 16.9% | 2.0% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Matagorda, TX | Lamar, TX | United States |
| Married Population | 54.4% | 56.0% | 49.8% |
| Currently Married | 54.4% | 56.0% | 48.0% |
| Married but Separated | 0.0% | 0.0% | 1.8% |
| Single Population | 45.6% | 44.0% | 50.2% |
| Never Married | 23.0% | 29.8% | 33.8% |
| Divorced | 14.7% | 9.0% | 10.8% |
| Widowed | 7.8% | 5.1% | 5.6% |
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| Household Size | 1.87 | 2.55 | 2.60 |
| Households | 231 | 516 | 124,010,992 |
| Family Households | 148 | 391 | 80,755,759 |
| Married couple, w/children | 14.2% | 8.7% | 30.5% |
| Married couple, no children | 66.2% | 55.8% | 42.9% |
| Non Family Households | 83 | 125 | 43,255,233 |
| Single householder, w/children | 0.0% | 30.4% | 15.8% |
| Single householder, no children | 19.6% | 5.1% | 10.8% |