| | Harper, KS | Medicine Lodge, KS | United States |
| Population | 1,250 | 1,364 | 329,725,481 |
| Female Population | 45.9% | 51.6% | 50.5% |
| Male Population | 54.1% | 48.4% | 49.5% |
| Median Age | 37.5 | 48.6 | 38.4 |
| space3 | | | |
| Population - 2010 | 1,467 | 2,014 | 309,327,143 |
| Population - 2000 | 1,567 | 2,193 | 285,036,114 |
| Population - 1990 | 1,735 | 2,453 | 251,960,433 |
| Pop. 2000 to Now | -17.5% | -17.7% | 15.6% |
| Pop. 1990 to Now | -25.5% | -26.5% | 30.8% |
| space4 | | | |
| Population Density | 772.1 | 1,140.5 | 93.4 |
| Land Area | 1.6 | 1.2 | 3,531,905.4 |
| Water Area | 0.0 | 0.0 | 264,836.8 |
| space | | | |
| Est. Total Population By Age | | | |
| | Harper, KS | Medicine Lodge, KS | United States |
| Age 0 to 4 | 3.9% | 6.0% | 5.9% |
| Age 5 to 9 | 6.8% | 4.9% | 6.1% |
| Age 10 to 14 | 9.8% | 3.2% | 6.6% |
| Age 15 to 17 | 3.3% | 3.7% | 3.9% |
| Age 18 to 20 | 3.8% | 3.3% | 4.0% |
| Age 21 to 24 | 2.3% | 6.6% | 5.2% |
| Age 25 to 34 | 15.0% | 7.9% | 13.8% |
| Age 35 to 44 | 17.3% | 8.9% | 12.9% |
| Age 45 to 54 | 9.6% | 16.6% | 12.6% |
| Age 55 to 59 | 3.7% | 7.6% | 6.7% |
| Age 60 to 64 | 4.3% | 7.0% | 6.3% |
| Age 65 to 74 | 10.6% | 14.4% | 9.6% |
| Age 75 to 84 | 5.4% | 3.7% | 4.5% |
| Age 85 and over | 4.1% | 6.2% | 1.9% |
| space1 | | | |
| Race | | | |
| | Harper, KS | Medicine Lodge, KS | United States |
| White | 85.0% | 93.3% | 59.4% |
| Black | 0.5% | 0.0% | 12.2% |
| Asian | 0.0% | 3.4% | 5.6% |
| Native American | 0.0% | 0.0% | 0.6% |
| Hawaiian, Pacific Islander | 1.0% | 0.0% | 0.2% |
| Other | 0.0% | 0.0% | 0.4% |
| Two or More Races | 5.5% | 0.1% | 3.2% |
| Hispanic | 7.9% | 3.2% | 18.4% |
| space2 | | | |
| Marriage & Family | | | |
| | Harper, KS | Medicine Lodge, KS | United States |
| Married Population | 52.4% | 55.2% | 49.8% |
| Currently Married | 51.6% | 51.8% | 48.0% |
| Married but Separated | 0.8% | 3.4% | 1.8% |
| Single Population | 47.6% | 44.8% | 50.2% |
| Never Married | 24.7% | 24.9% | 33.8% |
| Divorced | 14.8% | 12.8% | 10.8% |
| Widowed | 8.2% | 7.1% | 5.6% |
| space5 | | | |
| Household Size | 2.51 | 2.16 | 2.60 |
| Households | 494 | 620 | 124,010,992 |
| Family Households | 288 | 337 | 80,755,759 |
| Married couple, w/children | 29.5% | 25.2% | 30.5% |
| Married couple, no children | 45.5% | 53.1% | 42.9% |
| Non Family Households | 206 | 283 | 43,255,233 |
| Single householder, w/children | 11.8% | 16.0% | 15.8% |
| Single householder, no children | 13.2% | 5.6% | 10.8% |