Lacon is a city located in Marshall County Illinois. It is also the county seat of Marshall County. With a 2020 population of 1,721, it is the 513th largest city in Illinois and the 8201st largest city in the United States . Lacon is currently declining at a rate of -0.52% annually and its population has decreased by -11.15% since the most recent census, which recorded a population of 1,937 in 2010. Lacon reached it's highest population of in . Spanning over 2 miles, Lacon has a population density of 1,076 people per square mile.
The average household income in Lacon is $70,230 with a poverty rate of 14.78%. The median rental costs in recent years comes to $757 per month, and the median house value is $85,700. The median age in Lacon is 50.2 years, 44.4 years for males, and 54.2 years for females.