Fort Kaskaskia was a military outpost established by the French in 1703, located near the confluence of the Mississippi River and Kaskaskia River in present-day Illinois. It served as a strategic point for trade and defense during the colonial period, particularly against British expansion. The fort played a significant role during the American Revolutionary War, as it was captured by the Virginia militia in 1778. Today, the site is commemorated as a historic landmark, with remnants of the fort and a nearby state park that offers educational resources about its history and significance.