The Upper Peninsula was given to Michigan in an effort to settle the Toledo War (1835-1836) between Michigan and Ohio. Both states (although Michigan was really still a Territory) wanted the territory known as the Toledo Strip, and had even positioned militias on either side of the Maumee River! The boundaries of the disputed Toledo Strip Territory came into being when surveys were commission by each state to determine the extent of their territories. The conflicting survey results (based on a difference between the 1787 Northwest Ordinance and Ohio's Congressionally accepted State Constitution) was a swath of land between eight and five miles wide extending west from Lake Erie to the IN state line. Michigan had actually occupied the land for a few years after the surveys, collecting taxes and building roads in the area. Today, the new roads follow the old ones, and at "the old state line" many roads have an abrupt jog at that point where the OH roads were made to meet up with the old MI roads. Michigan's path to statehood was held up by the dispute, when it finally came to a head and militias were activated on both sides to fight for the Strip. When Michigan finally became a state, it was without the Toledo Strip, however, the Upper Peninsula was given in compromise. Michigan wasn't entirely satisfied with the solution however, since they still wanted part of Lake Erie itself and the matter wasn't officially settled until the case Michigan v. Ohio was heard before the United States Supreme Court in 1973. Since the U.P. was considered relatively worthless at the time it was given to Michigan, many people thought that Ohio had gotten the better end of the deal. Without the Toledo War, the U.P. would most likely be a part of Wisconsin today. This legendary boudary dispute had a lot of interesting twists and turns; you can find more information here: http://www.geo.msu.edu/geo333/toledo_war.html http://www.michigan.gov/dmva/0,1607,7-126-2360_3003_3009-16934--,00.html http://www.toledowar.com/ http://www.dnutt.com/articles/toledwar.htm