Brownstown, IL has a population of 710 and is the 17,388th largest city in the United States. The population density is 919 per sq mi which is 313% higher than the Illinois average and 915% higher than the national average. The median age in Brownstown is 37 which is approximately 1% lower than the Illinois average of 37. In Brownstown, 60% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 88% of Brownstown residents were born in Illinois, 12% were born out of state, 0% were born outside of the United States and 0% were foreign born.