Mackinaw, IL has a population of 2,196 and is the 10,494th largest city in the United States. The population density is 1,635 per sq mi which is 636% higher than the Illinois average and 1705% higher than the national average. The median age in Mackinaw is 38 which is approximately equal to the Illinois average of 37. In Mackinaw, 65% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 86% of Mackinaw residents were born in Illinois, 13% were born out of state, 1% were born outside of the United States and 0% were foreign born.