The answer dates back to 1703, when the French controlled the Illinois Country. That year a Jesuit group established its mission along the east bank of the Mississippi River to minister to the Kaskaskia tribe of Native Americans and founded a permanent settlement named for the group. They also set up a fur trading post there.

The town played an important role in Illinois’s early history. In 1741, King Louis XV sent a 140-pound bell to Kaskaskia. When George Rogers Clark captured the town from the British in 1778, during the Revolutionary War, the bell was rung in celebration, earning it the name the Liberty Bell of the West (although it is actually 11 years older than the one in Philadelphia).

In 1818, when Illinois became a state, Kaskaskia was its first capital. That was its peak, when the population was around 7,000. A year later, the capital was moved to Vandalia. Then, in 1881, the Mississippi River changed course and began flowing east of Kaskaskia, which not only wiped out much of the town but severed it from the rest of Illinois. In 1993, Kaskaskia was submerged by a flood. Today, it isn’t just the oldest town in Illinois, it’s also one of the smallest, with a population of 23 living in a few houses scattered across the floodplain.

Send your questions about the Chicago area to emcclelland@chicagomag.com.