French Missionaries Establish Kaskaskia

French Jesuit missionaries established Kaskaskia as a mission settlement in 1703, making it one of the earliest permanent European settlements in what is now the American midwest. Located on a navigable river island with access to both the Kaskaskia River and the Mississippi, the settlement grew rapidly as a center of the French fur trade. By the mid-18th century Kaskaskia had a population of several hundred French Creole residents, a substantial church, and the administrative apparatus of New France's Illinois Country.

The town's French character — Catholic, French-speaking, organized around kinship networks and the fur trade — would prove crucial when George Rogers Clark arrived in 1778. The French Creoles were not enthusiastic British subjects, having been transferred to British rule against their will in 1763. Their ambivalence about the British gave Clark an opening that a town of committed Loyalists would not have provided.