Hartsburg, IL has a population of 251 and is the 23,406th largest city in the United States. The population density is 1,815 per sq mi which is 696% higher than the Illinois average and 1903% higher than the national average. The median age in Hartsburg is 44 which is approximately 16% higher than the Illinois average of 37. In Hartsburg, 59% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 88% of Hartsburg residents were born in Illinois, 10% were born out of state, 0% were born outside of the United States and 2% were foreign born.