The Constitution of the State of Michigan is the governing document of the U.S. state of Michigan. It describes the structure and function of the state's government. There have been four constitutions approved by the people of Michigan. The first was approved on October 5 and 6, 1835, written as Michigan was preparing to become a state of the Union, which occurred in January 1837. Subsequent constitutions were ratified in 1850 and 1908. The current constitution was approved by voters in 1963.