Skip to main content

Territorial Era, 1776-1818

The capture of Kaskaskia by a small American revolutionary army in July 1778 established a claim by the new United States to the Illinois Country. The 1783 Treaty of Paris formally awarded the area west of the Mississippi River to the new nation. Many French settlers crossed the Mississippi, uneasy with the thought of living under American government. Others stayed on, operating businesses and participating in establishing the new government.