Evolution of Michigan’s Legal Boundaries August 9, 1842, marked a turning point in Michigan’s map—and the map of the entire U.S.—when the Webster-Ashburton Treaty was signed, settling several long-standing border disputes between the United States and Great Britain. Among the many results of this treaty was the decision that Sugar Island (then known to Canadians as St. George’s Island) in the St. Mary’s River would become part of Michigan and the United States. At the heart of the treaty were the efforts of U.S. Secretary of State Daniel Webster and British diplomat Lord Ashburton to put an end to growing… Read More »












