Encompassed by four of the five Great Lakes, the Midwest state of Michigan has the world's largest freshwater coastline. The state consists of an “upper” and “lower” peninsula connected by the five-mile Mackinac Bridge. Michigan is known as the birthplace of the automobile industry and is home to the “Big Three” American automakers: Chrysler, General Motors, and Ford. Fierce competition from foreign companies in recent decades has caused a decline in the American automotive industry. The ensuing loss of domestic market share and Michigan’s over-reliance on a single industry has caused the state’s economy to perform below the national average. Michigan is now attempting to diversify its economy by focusing on life sciences, alternative energies, tourism, and defense. It is also a leader in other manufacturing businesses including cereal, machine tools, airplane parts, home appliances, hardware, and furniture.