Nevertheless, following a year of consideration, Dorchester relented and settled on St. Joseph Island as the site for the new fort to replace Mackinac. The site was preferred to other locations on the mainland including Thessalon and Sault Ste. Marie as it had a relatively deep shoreline suited to large vessels. On April 11, 1796, Dorchester ordered a garrison of 14 men to set up a camp on the southwest corner of the island close to the channel between Mackinac and Sault Ste. Marie in order to prevent the island being claimed by the Americans. This advance detachment, led by Lieutenant Andrew Foster of the Queen's Rangers identified a spot of high ground nearby to suitable for a fort. In accordance with the Jay-Grenville Treaty, the British abandoned Mackinac Island in June 1796 to establish a new fort on the southeastern corner of the island. Subsequently, commanders in Quebec sent orders on July 5, 1796 that the garrison occupying the island could not be removed except on orders from the Governor General.