Which entity is this text about?

David Thompson was born in Westminster, Middlesex, to recent Welsh migrants David and Ann Thompson. When Thompson was two, his father died. Due to the financial hardship with his mother without resources, Thompson and his older brother were placed in the Grey Coat Hospital, a school for the disadvantaged of Westminster. Thompson graduated to the Grey Coat mathematical school, where he was introduced to basic navigation skills.

Upon his arrival back in Montreal, Thompson retired with a generous pension from the North West Company. He settled in nearby Terrebonne and worked on completing his great map, a summary of his lifetime of exploring and surveying the interior of North America. The map covered the wide area stretching from Lake Superior to the Pacific, and was given by Thompson to the North West Company. Thompson's 1814 map, his greatest achievement, was so accurate that 100 years later it was still the basis for many of the maps issued by the Canadian government. It now resides in the Archives of Ontario.  In 1815, Thompson moved his family to Williamstown, Upper Canada, and a few years later was employed to survey the newly established borders with the United States from Lake of the Woods to the Eastern Townships of Quebec, established by Treaty of Ghent after the War of 1812. In 1843 Thompson completed his atlas of the region from Hudson Bay to the Pacific Ocean.  Afterwards, Thompson returned to a life as a land owner, but soon financial misfortune would ruin him. By 1831 he was so deeply in debt he was forced to take up a position as a surveyor for the British American Land Company to provide for his family. His luck continued to worsen and he was forced to move in with his daughter and son-in-law in 1845. He began work on a manuscript chronicling his life exploring the continent, but this project was left unfinished when his sight failed him completely in 1851.
David Thompson (explorer)