In 1753 the fort was in such bad condition that it was decided to build anew, this time of stone, brought from the bluff. When completed, the new structure was one of the strongest forts ever built in America.
An English traveler who visited the new fort in 1765, when the British were in control, told of finding walls two feet two inches thick, pierced with loopholes at regular distances, and with two portholes for cannon in the faces, and two in the flanks of each bastion. There was a ditch, but this had not been completed. The entrance was a handsome rustic gate. Within the fort he found the houses of the commander and of the commissary, the magazine for stores, and the quarters of the soldiers. There were also a powder magazine, a bunk house, and a prison.
The visitor told how the bank of the Mississippi was continually falling in, and so was threatening the fort. In the effort to control the destructive current a sand bank had been built to turn it from its course; the sand bank had become an island, covered by willows. Yet it was realized that the destruction of the fort was sure.
“When the fort was begun, in the year 1756,” he wrote, “it was a good half mile from the water side; in the year 1766 it was but eighty paces; eight years ago the river was fordable to the island; the channel is now forty feet deep.”
In the year 1764 there were about forty families in the village near the fort and a parish church served by a Franciscan friar. In the following year, when the English took possession of the country, they abandoned their houses, except three or four poor families, and settled at the village on the west side of the Mississippi, choosing to continue under the French government.
An English visitor who saw Fort Chartres in 1766, when it was still in its prime, wrote of his impressions:
“The headquarters of the English commanding officer is now here, who in fact is the arbitrary governor of the country. The fort is an irregular quadrangle; the side of the exterior polygon is 490 feet. It is built of stone plastered, and is only designed as a defense against the Indians, the wall being two feet two inches thick, and pierced with loopholes at regular distances, and with two portholes for cannon in the face and two in the flank of each bastion.
“It is generally agreed that this is the most commodious and best built fort in America.”
In 1772 a flood washed away part of the fort, on which a million dollars had been spent—a large amount for that day. The garrison fled north to Kaskaskia, where another fortress was built.
More than sixty years later the Illinois Gazetteer said: