Sister cities of Ann Arbor, Michigan

Ann Arbor is a city in the US state of Michigan and the county seat of Washtenaw County. The 2010 census recorded its population to be 113,934, making it the fifth largest city in Michigan. The Ann Arbor Metropolitan Statistical Area (MSA) includes all of Washtenaw County, which had a population of 344,791 as of 2010. The city is also part of the larger Detroit–Ann Arbor–Flint, MI CSA.

Ann Arbor was founded in 1824, with one theory stating that it is named after the spouses of the city's founders and for the stands of trees in the area. The University of Michigan moved from Detroit to Ann Arbor in 1837, and the city showed steady growth throughout the 19th and 20th centuries, except during the Depression of 1873. During the 1960s and 1970s, the city gained a reputation as a center for left-wing politics. Ann Arbor became a focal-point for political activism and served as a hub for the civil-rights movement and anti-Vietnam War movement, as well as various student movements.

Ann Arbor is home to the University of Michigan, a world-renowned institution of higher education. The university shapes Ann Arbor's economy significantly as it employs about 30,000 workers, including about 12,000 in the medical center. The city's economy is also centered on high technology, with several companies drawn to the area by the university's research and development money, and by its graduates.