List of commandants of the Illinois Country

The Illinois Country was governed by military commandants for its entire period under French and British rule, and during its time as a county of Virginia. The presence of French military interests in the Illinois Country began in 1682 when Robert de La Salle built Fort St. Louis du Roche on the Illinois River. The commandant of the fort was the top French official in the region and was responsible to the Governor General of New France. In 1718 Illinois was transferred to Louisiana and renamed Upper Louisiana. The new seat of government was Fort de Chartres, located in what is now southeastern Illinois among the growing French settlements of Cahokia, Kaskaskia and Prairie du Rocher.

In 1763, at the conclusion of the Seven Years' War, the entire area of Louisiana was divided, with Great Britain receiving the lands east of the Mississippi and Spain claiming the lands west of it. The new city of St. Louis, in present-day Missouri, became the seat of government of Spanish Upper Louisiana. The government of the British side, present-day Illinois, remained in the hands of military commandants at Fort de Chartres; upon that fort's abandonment the seat of government moved to Kaskaskia. British rule in Illinois was ad hoc and unsystematic. The Quebec Act of 1774 would have organized a government for the region, but before it could be put into effect Illinois was captured by Virginia militia in the Illinois Campaign.

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