Southwestern U.S. - some elements of civil law. Louisiana - much civil law. Federal sources of law. Contract by which states gave up some of their rights to govern themselves in exchange for the benefits of a national government. Broadly sets forth a national governmental scheme.
Federal government takes care of national concerns.
Enumerated powers - Article I, Section 8. Living constitution - scope of national concerns has greatly increased as constitution is flexibly interpreted depending on the circumstances. State and local governments take care of state and local concerns. Article I, Section 9. Legislative branch - makes the law.