McLeansboro, IL has a population of 2,801 and is the 9,145th largest city in the United States. The population density is 970 per sq mi which is 336% higher than the Illinois average and 970% higher than the national average. The median age in McLeansboro is 42 which is approximately 13% higher than the Illinois average of 37. In McLeansboro, 61% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 77% of McLeansboro residents were born in Illinois, 22% were born out of state, 1% were born outside of the United States and 0% were foreign born.