Sault Ste. Marie was destined to be a gathering place. Native Americans relied on the rapids of the St. Mary's River, which links two Great Lakes, Superior and Huron, for a year-round supply of fish. Its population swelled in the summer--a tradition that continued as French traders came to turn in their pelts and celebrate the end of another long, hard winter. After the Revolutionary War, the Sault, as it is called, became a community divided on national...