Lewistown, IL has a population of 2,385 and is the 10,098th largest city in the United States. The population density is 1,193 per sq mi which is 437% higher than the Illinois average and 1217% higher than the national average. The median age in Lewistown is 44 which is approximately 17% higher than the Illinois average of 37. In Lewistown, 63% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 91% of Lewistown residents were born in Illinois, 7% were born out of state, 0% were born outside of the United States and 2% were foreign born.