Fort Mackinac
The British built the fort during the American Revolutionary War to control the strategic Straits of Mackinac between Lake Michigan and Lake Huron , and by extension the fur trade on the Great Lakes . 
<triplet> American Revolutionary War <subj> British <obj> participant <triplet> Lake Michigan <subj> Great Lakes <obj> part of <triplet> Lake Huron <subj> Great Lakes <obj> part of