Maybe Conrad Black but historically the answer could have been The Hudson Bay Company, except back then there wasn't a Canada like there is today so the land they claimed was theirs.
Also land in todays Canada is not always "owned" by Canada. Canada is a Confederation of many Nations and those Nations do own their own land.
The French and British both had extensive land claims in Canada (leaving out the other obvious group, the native tribes).
Prairie
England covers 50,346 square miles, Canada's area is 3,854,085 square miles - making Canada 75 times times larger !
The British American land claims of 1815 were claims acted uppon the fact that the United states had taken it's independence from the British government and brittain had to take some land. so they took Canada
In 1763, England controlled Canada and the French land east of Mississippi River. Those were some of the territories and colonies that are now part of modern Canada.
England
England.
The Choctaw and Ojibwe were two of thr tribes that had claims on it that weren't honored by European immigrants.
John Cabot!
Canada and Land's End are on the 50th parallel, so Canada is due West of Land's End.
John Cabot is often regarded as the discoverer of Canada, having arrived on its shores in 1497 under the commission of King Henry VII of England. Although Indigenous peoples inhabited the land long before his arrival, Cabot's voyage marked the beginning of European exploration and claims in North America. His expedition is significant for establishing England's interest in the New World.
You are confusing two things:-Land Area. (Canada is 40 times as big as England by area).Population density - that is the number of people living in a unit area. (People live much closer together in England - even outside cities - than they do in Canada).