Augusta, IL has a population of 455 and is the 20,138th largest city in the United States. The population density is 636 per sq mi which is 186% higher than the Illinois average and 602% higher than the national average. The median age in Augusta is 47 which is approximately 26% higher than the Illinois average of 37. In Augusta, 58% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 84% of Augusta residents were born in Illinois, 15% were born out of state, 0% were born outside of the United States and 1% were foreign born.