For many years, Sault Ste. Marie was the stopping off point for many of the independent fur traders as they made their way north and west from Montreal. The independents, recognizing that there is strength in numbers, came together to form the North West Company in 1779. The partnership was renewed in 1780 for a further three years but, before the tenure could expire, the independents had reverted to their old ways. The principal traders in the partnership regrouped in January of 1784. This time the partnership lasted until 1797 when a splinter group, fed up with the oppressive actions of Simon McTavish, head of the North West Company, formed Richardson and Forsyth and Company, more commonly known as the XY Company. Following the death of McTavish in 1804, the North West Company and the XY Company merged forming the new North West Company. The North West Company maintained a post including houses and stores at what is now Sault Ste. Marie, Michigan until about 1790. The Company relocated to the British side of the St. Mary's River as a result of the Jay Treaty . Once relocated, the Company built docks, a sawmill, storehouses and dwelling houses and, perhaps most importantly, a canal and lock which permitted the passage of bateaux through the circumvention of the Rapids. In 1799, before the reunification, the North West Company applied to the government of Upper Canada for a grant of the land which the Company occupied at Sault Ste. Marie. The request was opposed by the XY Company on the grounds that this type of grant would undoubtedly benefit the North West Company but, at the same time, it would be injurious to all other fur trade outfits including the independents. It was the recommendation of the XY Company that if a grant was to be made to one company then similar grants should be made to all fur trading outfits including the XY Company and the Hudson's Bay Company. Although the war of words and petitions continued throughout the next several years, it became a moot point with reunification. The entire post, including the canal, was destroyed by American troops during the War of 1812. The North West Company rebuilt the post but occupied it only until 1821 when the North West Company and the Hudson's Bay Company merged and the Hudson's Bay Company took over the post. The Hudson's Bay Company maintained a factor and other employees at the post until 1867 when the last factor, Wemyss Mackenzie Simpson resigned to become the first Member of Parliament for the District of Algoma following Confederation. Following his departure from the post, a caretaker maintained the post but within a matter of years it fell into disuse. The buildings either fell down or were torn down until all that remained was the stone powder magazine. In 1922 the Sault Ste. Marie Historical Society was actively planning for Discovery Week. A representative of the Society wrote to Francis H. Clergue and asked what the Block House looked like at the point in time when he acquired it and what changes he made to it in order to convert it from a powder magazine to living accommodations. By way of response, Clergue wrote back to say that he had no firm recollection as to when he began work on the structure but that it was some time after he acquired the property from the Hudson's Bay Company. According to the letter from Clergue, which was printed in its entirety in the Sault Daily Star on 7 July 1922, only the lower stone storey then existed. The property was surrounded by a heap of large boulders. Here and there, stumps of the original post stockade that had surrounded the post stuck up out of the ground. Since the stumps couldn't be driven into the ground, Clergue used the boulders and the stumps to build a stone fence or wall around the property. The original building consisted of one large room lighted only by small holes about 6 inches square that were built into the wall. From the fact that the holes were shoulder height, Clergue surmised that they were for gun barrels. He divided the room in two with a brick wall creating a small reception room in the front and a kitchen in the back. He then replaced the original small iron door with a larger oak door and cut windows in the stone walls. The small gun barrel holes were not filled in but rather were covered with permanent shutters. The next step was the construction of the second floor. Clergue had cedar trees of an appropriate length cut so as to not only cover the stone portion of the building but also to overhang the building, creating additional living space. According to Clergue, he intended to create a building that was of the "proper architectural style of a block house of the period of the Indian Wars..." Clergue ultimately constructed a mansion for himself and his family in 1902. He and his brother moved out of the Block House and into the new house, Montfermier, where their parents and two of their sisters joined them. Clergue continued to use the Block House as an office until his departure from Sault Ste. Marie as did his brother Bertrand. Thereafter, it was used as a residence for a succession of night watchmen at the paper mill until the building was extensively damaged by fire in 1974. The Block House entered a new phase in its history in 1979 when the Sault Ste. Marie Local Architectural Advisory Committee (LACAC) requested that City Council designate the Block House as having architectural and historical value under Part IV of the Heritage Act. City Council agreed and passed a by-law to that effect on December 1979. In a 1982 LACAC report, the building is described as being an unassuming building having three levels. The base level, which measures 22 feet by 28 feet, is constructed of uncut field stone and red mortar. The second and third levels are cantilevered and extend beyond the base by approximately 39 inches on each side. The structure is topped with a hip roof. As Clergue had indicated in his letter to the Historical Society, he had cut out windows in the stone portion of the building. When LACAC surveyed the building, two windows were found on adjoining walls of the building. Although Clergue didn't describe the window structure of the second and third levels of the building, three windows in each of the four walls were evident.