Sunday, February 17, 2019


Marker Details

Historical Marker:

Fort De Chartres-Prairie Du Rocher, Illinois

The marker is located off the southwest side of IL 155 in the parking area of Fort de Chartres State Park.
No coordinates identified
Dedication Date:
Dedication By:
Division of Highways and The Illinois State Historical Society

Marker Description:
The fertility of the Mississippi bottom lands in this area attracted settlers early in the eighteenth century. The territory was under French rule and in 1718 Pierre Duque, Sieur de Boisbriant, commandant of the Illinois country, was sent to erect a permanent military post. The First Fort de Chartres was completed in 1720. Built of wood and exposed to the Mississippi floods, the fort had to be rebuilt in 1727 and 1732. In 1753 construction of a new fort built of stone and farther inland begun under the direction of Francois Saucier. When it was completed in 1756 it was considered one of the finest forts in North America. The British gained control of the area in 1763 by the Treaty of Paris and in 1765 took possession of the fort which they renamed Fort Cavendish. They destroyed the fort in 1772 when the encroaching Mississippi waters necessitated its abandonment. It had served as the seat of civil and military government in the Illinois country for over half a century. The partially reconstructed fort is a state memorial west on Illinois 155. Prairie du Rocher, the small French village four miles east of the fort, was founded in 1722 by St. Therese Langlois, nephew of Boisbriant. The Prairie du Rocher Common (land used by all the villagers) was granted to the village by the territorial government in 1743 and was used until 1852. Prairie du Rocher, 'Field of the Rock,' remains a picturesque village where French Christmas and New Year's customs are still observed.

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