I'll answer best as I can.
The great Lakes are on the border between Canada and the United states. More in depth,
Lake Erie touches ~ New York, Pennsylvania, Ohio, and Michigan,
Lake Ontario ~ New York, and the Canadian Province of Ontario,
Lake Huron ~ US state of Michigan, and the Canadian Province of Ontario,
Lake Michigan ~ Indiana, Illinois, Wisconsin, and Michigan,
Lake Superior ~ Minnesota, Wisconsin, and Michigan, and the Canadian province of Ontario.
They have contributed a lot to the economic evolution of the United States and Canada, and are usually used to transport materials, food etc. to other countries. They hold about one fifth of the worlds freshwater supply.