Pocahontas, IL has a population of 767 and is the 16,887th largest city in the United States. The population density is 1,021 per sq mi which is 359% higher than the Illinois average and 1027% higher than the national average. The median age in Pocahontas is 41 which is approximately 9% higher than the Illinois average of 37. In Pocahontas, 56% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 85% of Pocahontas residents were born in Illinois, 15% were born out of state, 0% were born outside of the United States and 1% were foreign born.