The History of the Fort
The Illinois territory was scarcely populated by western Europeans at the start of the 18th century. The first non-natives to explore the area were French explorer Louis Jolliet and Catholic priest/missionary Jacques Marquette. Together they mapped much of the Mississippi river from the Great Lakes to within about 435 miles of the Gulf of Mexico in 1673.
By the end of the century, missionaries from Canada were eager to evangelize natives in the newly mapped territory. One of the first arrivals was in 1699, with the village of Cahokia founded by French missionaries from the seminary of foreign missions in Quebec. Four years later, rival Jesuit missionaries founded the village of Kaskaskia just south of Cahokia along the Mississippi.
As these villages slowly developed and ties with native groups became stronger the economy started to grow and diversify. Fur trading, mineral mining, and agricultural development of the richly fertile Mississippi valley caught the interest of the French government who started to see the area as a strategic and potentially profitable area to develop. This was especially true with the founding of New Orleans in 1718. With exports coming in and out of the new port city, it was important to establish different protection points along the Mississippi river all the way to the Great Lakes, where goods could be delivered to colonial Canada.
The same year New Orleans was founded, provincial official Pierre Duqué Sieur de Boisbriant was ordered to the Illinois territory to establish a military presence in the area. Boisbriant arrived at Dauphin Island (present day Alabama) March 6, 1718 and spent the summer in the southern Louisiana territory. In October of that year, he left for Illinois and arrived in Kaskaskia in late December. Upon arrival, he was instructed to bolster French defenses along the Mississippi valley.
Working with John Law’s Company of the West (also known as the Mississippi Company), Boisbriant completed the first iteration of Fort de Chartres in 1721. The site for the fort was chosen to be almost equidistant from Cahokia and Kaskaskia so as to allow the military to reach each respective village in a timely manner in the case of an emergency. The location may have also been chosen for economic reasons because it allowed easy access to rich lead mines west of the Mississippi river.
Fort de Chartres, named after the son of the Regent of France, became the administrative headquarters of French colonial Illinois. The commandant of the fort was the military leader and governor of the territory and he held the only private residence within the fort’s walls. This made Boisbriant the first leader of the fort and area when he arrived in 1718. Civil and criminal trials were also conducted there and it became a central trading post where traders from the Mississippi company stored their wares. The chapel at the fort was used by the men who lived within its walls. Sometimes the priest of St. Anne’s de Fort de Chartres (the church just outside the walls of the gate that eventually became St. Joseph’s church) also conducted services at the chapel as well as ceremonies, like weddings.
The same year the Fort was finished a small town formed outside the gates named Nouvelle Chartres. Many of the military personnel preferred to live in the village rather than the fort. Living in the village gave them a better opportunity to raise families and build farms. By 1722, there was an estimated 700 non-native persons in the Illinois country. A year later in June 1723, a census completed by M. Diron d’Artaguiette, inspector-general of the colony found, “39 inhabitants, 42 white laborers, 28 married women, and 17 children” at Fort de Chartres. This census did not include the black slave population of the fort.
The original Fort de Chartres had two bastions and a wooden palisade, along with four buildings within the walls. The palisade walls were approximately 190 feet long. The proximity of the fort and choice to use a wood palisade rather than stone or bricks created immediate issues with the fort. Mississippi river overflow regularly flooded the area and the wooden structures became damaged and rotted. By 1725, a second Fort de Chartres was already under construction. The exact location of site II isn’t clear. Some sources suggest it was rebuilt on the same site as the first fort, but others claim it was a completely different site, albiet very close to the original.
Regardless, the second fort was completed sometime between 1728 and 1732. This iteration was smaller but had much stronger defenses with four bastions rather than two and a double palisade wall with earth us to fill between the walls. Despite the stronger build, this fort suffered the same problems as the first Fort de Chartres. The decision to not move it further inland spelled doom for the future of the structure. The wooden construction of the defensive walls paired with damp Spring months and incessant flooding from the Mississippi led to the fort being abandoned for Kaskaskia in 1747 until a new Fort de Chartres was completed further from the Mississippi.
Construction began on Fort de Chartres III in 1753 and was reported as complete by 1756 at an enormously high cost of 5 million livres. Rumors persisted that the fort was not actually finished until 1760 but only reported as done in 56’ by the governor of New Orleans to calm concerns of the crown related to the high price. The early reporting may have also been done to bolster the defensive image of French forces amongst rising tensions with the British in colonial North America.
Fort de Chartres III had four bastions like the second fort, but it was constructed of an estimated 24” thick stone wall rather than wooden palisades. The walls had gun loops at regular intervals and portholes for two cannons at every bastion. The original main gate faced the Mississippi River and the entire stone wall surrounding the fort was covered in a bright white limestone mortar.
French occupation of Fort de Chartres III was short-lived. Following their defeat in the French and Indian War in 1763, all French-occupied lands east of the Mississippi were awarded to the British. The redcoats officially acquired the fort from the French on October 10, 1765, and renamed it, Fort Cavendish, in honor of the Colonel who took control in early 1766. The British inhabitants experienced the same flooding issues the French struggled with throughout the first half of the century and quickly abandoned the fort in 1772 just seven years after officially taking command.
After the British left, the fort quickly fell into disrepair. The southern wall collapsed from a flood shortly after and by the early 19th century locals reported large trees growing within the walls. The only building known to be used was the powder magazine, which became a horse and hog stable for a neighboring farmer. Visitors to the fort throughout the 19th century noted the poor condition of the walls and buildings at the fort, besides the magazine, which was regularly praised for its good condition. By the late 1840s, a local farmer built a cabin within the crumbling walls and much of the existing structures had been stripped of materials by others in the area looking for stone and other supplies.
American historian Edward Gay Mason visited the fort in 1879 for a research trip and described it as follows:
“Entering the enclosure through a rude farm-gate, which stands just in the place of its lofty predecessor of carved stone, the line of the walls and the corner bastions can be readily traced by the mounds of earth covered with scattered fragments of stone, beneath which, doubtless, the heavy foundations remain, except at the corner swept away by the river. On two sides the outline of the ditch can be seen, and the cellars of the commandant’s and intendant’s houses, and of the barracks, are plainly visible, half filled with debris, under which, perhaps, the old cannon of Louis XIV are still lying.”
The only building that remained was the “picturesque and venerable” magazine.