Limestone, IL has a population of 1,562 and is the 12,460th largest city in the United States. The population density is 597 per sq mi which is 169% higher than the Illinois average and 559% higher than the national average. The median age in Limestone is 44 which is approximately 17% higher than the Illinois average of 37. In Limestone, 60% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 87% of Limestone residents were born in Illinois, 12% were born out of state, 1% were born outside of the United States and 0% were foreign born.