State Governments
Each of the fifty states has its own constitution and government. State constitutions differ to some extent, although these constitutions cannot be contrary to the Constitution of the United States, and the Constitution requires the federal government to ensure that each state maintains a republican form of government. Most state constitutions include a system of separation of powers or checks and balances similar to the U.S. Constitution. Forty-nine states have a bicameral (two-house) legislature (Nebraska, which has a unicameral, or one-house legislature, is the sole exception), an executive (the Governor), and a system of courts, including a state Supreme Court. (The legal system in Louisiana differs from those of other American states because it is based to a large extent on the French Napoleonic Code, instead of the Anglo-American legal system that predominated elsewhere.)
The Constitution requires each state to give "full faith and credit" to the laws and judicial decisions of other states. This provision, along with the power of Congress power to regulate commerce between the states, was included in the Constitution to prevent states from engaging in commercial rivalries with one another by enacting laws hostile to businesses or citizens from neighboring states.