Quincy, known as the 'Gem City', is a medium sized city in Adams County, Illinois, United States. The population was 40,366 at the 2000 census. The city also serves as the county seat of Adams County. It lies on the bluffs along the Mississippi River about 100 miles north of Saint Louis and is the western most city in the state. Located between Keokuk, Iowa and Hannibal, Missouri, Quincy is the largest anchor city of the Quincy-Hannibal Micropolitan Area. Quincy has a strong connection to the 19th century river city nostalgia popularized by celebrated author Mark Twain's books and fictional characters 'Tom Sawyer' and 'Huckleberry Finn'. Quincy apartments for rent comparison page shows most up to date rent information on Quincy apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.