1. Michigan became a state: June 15, 1837 is the day Michigan officially became a state of the United States. It was the 26th state to be admitted to the Union.

2. The Detroit River Tunnel opened: On June 15, 1910, the Detroit River Tunnel opened, connecting Detroit, Michigan, to Windsor, Ontario, in Canada. The 2.6-mile tunnel was the first underwater vehicular tunnel in the world.

3. The Michigan State Capitol opened: The Michigan State Capitol in Lansing opened on June 15, 1879. It was designed by Elijah E. Myers and features a cast-iron dome that is painted a deep blue.

4. The Mackinac Bridge opened: The Mackinac Bridge, which spans the Straits of Mackinac and connects Michigan's Upper and Lower Peninsulas, opened on June 15, 1957. At the time, it was the longest suspension bridge in the world.

5. Henry Ford II was born: Henry Ford II, the grandson of Ford Motor Company founder Henry Ford, was born on June 15, 1917, in Detroit, Michigan. He was the president of Ford Motor Company from 1945 to 1960 and helped lead the company to become one of the largest corporations in the world.