For the fifth-straight Olympics the United States won more medals than any other county, and athletes with ties to the state of Michigan played a major role in that. As Off Tackle Empire notes, four medals came from University of Michigan athletes:
Tyler Clary - USA Men's Swimming: 200m Backstroke
Betsey Armstrong - USA Women's Water Polo
Janine Hanson - Canada Women's Rowing: Eight w/Coxswain
Peter Vanderkaay - USA Men's Swimming: 400m Freestyle
Michigan State did not have a medalist and had only one representative in London, the fewest among Big Ten schools.
Michael Phelps was the most notable athlete with Michigan ties, as he earned six medals total. Tyler Clary established a new Olympic record in winning the 200 meter backstroke.
Here are other athletes with ties to the state of Michigan that won medals:
Claressa Shields - Women's Middleweight Boxing - Gold - United States
Jordyn Wieber - Women's Artistic Gymnastics (Team Competition) - Gold - United States
Janine Hanson - Women's eights rowing - Silver - Canada
Peter Vanderkaay - Men's 400-meter Freestyle Swimming - Bronze - United States
Betsey Armstrong - Women's Water Polo - Gold - United States