Fort Chambly Fort Chambly is a historic fort in La Vallée - du - Richelieu Regional County Municipality , Quebec . The fort is designated as a National Historic Site of Canada . Fort Richelieu was part of a series of five forts built along the Richelieu River . Fort Richelieu is at the mouth of the Richelieu River . Fort Chambly formerly known as Fort St . Louis at Chambly , Fort Sainte Thérèse , and Fort Saint - Jean at Saint - Jean - sur - Richelieu , are on the way . Fort Sainte Anne ( Isle la Motte , Vermont ) in Lake Champlain is near its source . The forts were built in order to protect travellers on the river from the Iroquois . The region is informally known as la Vallée - des - Forts . History . Fort Chambly at the foot of the Chambly rapids on the Richelieu River in Quebec , Canada , was built by the French in 1711 . It was the last of three forts to be built on the same site . The first — then called Fort Saint Louis — was constructed in 1665 by captain Jacques de Chambly , to protect New France from Iroquois attacks . After minor repairs , the fort was burned by the Indians in 1702 , but was reconstructed in 1702 . By then it was already known as Fort Chambly . However with the Great Peace of Montreal in 1701 , the war between the French and Iroquois was over . Also at this time the War of the Spanish Succession broke out , and boiled over into the colonies of France and England . Thus , to defend against a more powerful European attack , including the threat of cannons , Governor Philippe de Rigaud Vaudreuil ordered that the fort be rebuilt in stone in 1709 . The engineer responsible for the design and construction of the new fort was Josué Boisberthelot de Beaucours . He also oversaw major improvements carried out on the fort between 1718 and 1720 , modifications he felt would greatly increase the fort ' s defenses . For many years Fort Chambly was the main footing of the defensive chain of fortifications along the Richelieu River , which was the easiest invasion route into New France . However , with the construction of Fort Saint - Frédéric ( 1731 ) and Fort Saint - Jean ( Quebec ) ( 1748 ) further south , Fort Chambly lost most of its defensive raison d ' etre and so was converted into a warehouse and rally - point for soldiers , although the fort was never abandoned . With the Seven Years War , Fort Chambly was re - fortified and reoccupied , although it failed to stop the British from approaching Montreal and Quebec . The substantial stone structure which still stands today was lost to the British in 1760 in The Conquest of New France , also known as the French and Indian War . Captured by American forces on October 20 , 1775 during the American Invasion of Canada of 1775 - 76 , it was held until the spring of 1776 when it was evacuated and burned , as the Americans retreated southward to Fort Ticonderoga . Subsequently , prisoners - of - war from the Continental Army , including Colonel William Stacy , were held at Fort Chambly until the end of the American Revolutionary War . After the Fenian Raids in the 1860s , during which the fort was reoccupied , it was allowed to fall into ruin . In 1882 a citizen of Chambly , Joseph - Octave Dion , personally repaired and restored the site . In the 20th century the Canadian government recognized Fort Chambly ' s cultural and historical worth and undertook its maintenance . Between 1965 and 1985 extensive archaeological digs were carried out , and today a fully reconstructed version of the final phase of Fort Chambly ( 1718 – 1720 ) is maintained by Parks Canada and is open to the public as Fort Chambly National Historic Site of Canada . Legacy . On 28 June 1985 Canada Post issued ' Fort Chambly , Que . ' one of the 20 stamps in the “ Forts Across Canada Series ” ( 1983 & 1985 ) . The stamps are perforated 12Â½ x 13 and were printed by Ashton - Potter Limited based on the designs by Rolf P . Harder . Affiliations . The Museum is affiliated with : CMA , CHIN , and Virtual Museum of Canada .