Because they are
The Great Lakes are sometimes called the Freshwater Sea or the Inland Sea, but most of the time they are just called the Great Lakes.
You can boat the entire Great Lakes system. 4 of the 5 Great Lakes constitute the border between Canada and the USA. Chicago is the farthest point from the Canadian border, so it would take a long time to get there.
Canadian is half covered by the Canadian shield. The shield goes from the Great Lakes to the Arctic Ocean.
The lakes that separate the United States of America and Canada is actually called the "great lakes". There are not these lakes across the whole border of Canada, because most of them are more to the east. If you have noticed, if you put all the great lakes together, they spell "HOME".
There is Niagra Falls which is shared by Ontario(Can.) and New York(U.S.), the Rocky Mountains which run from British Columbia(Can.) to New Mexico(U.S.), the great plains, and the Great Lakes.
canadian shield
Ontario
No Canadian provinces border Illinois
Lake Superior ?
yes
Great bear lake.
The great lakes are the most densely populated of those regions.
The Great Lakes are sometimes called the Freshwater Sea or the Inland Sea, but most of the time they are just called the Great Lakes.
The five lakes you are inerested in are the Greta Lakes. Only Lake Michigan is entirely in the US. Lakes Superior, Huron, Erie and Ontario straddle the US/Canadian border. There is a sixth lake in the group (St. Clair) which is considerably smaller, it is also on the border.
Hmmm ONTARIO
Ontario
All the Great lakes are shared by Canada and the US except lake Michigan which has no Canadian shoreline.