Lacon, IL has a population of 1,837 and is the 11,518th largest city in the United States. The population density is 1,148 per sq mi which is 416% higher than the Illinois average and 1167% higher than the national average. The median age in Lacon is 45 which is approximately 21% higher than the Illinois average of 37. In Lacon, 62% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 86% of Lacon residents were born in Illinois, 13% were born out of state, 0% were born outside of the United States and 1% were foreign born.