Monroe County, Michigan Monroe County, Michigan Monroe County is a county located in the U.S. state of Michigan. As of the 2010 census, the population was 152,021. The largest city and county seat is Monroe. The county was established as the second county (after Wayne County) in the Michigan Territory in 1817 and was named for then-President James Monroe. Monroe County comprises the Monroe, MI Micropolitan Statistical Area and is included in the Detroit-Warren-Ann Arbor, MI Combined Statistical Area. It is also considered a northerly extension of the Toledo Metropolitan Area. Before the county's formation, the primary settlement was Frenchtown, which was settled
Monroe, Michigan Arbor-Flint combined statistical area, and the city is sometimes unofficially included as a northerly extension of the Toledo Metropolitan Area. The Monroe area saw several military conflicts during the War of 1812 with Great Britain and is best remembered for the Battle of Frenchtown. In 1817, portions of the Frenchtown settlement along the River Raisin were platted and renamed Monroe after then-president James Monroe. When Michigan became a state in 1837, Monroe was incorporated as a city. Monroe is known as the childhood residence of George Armstrong Custer and other members of his family, including his brother Boston Custer and