1. Sources of American Law
American law is layered: constitutions set the outer boundary, statutes and administrative regulations fill in the details, and courts interpret both through common-law precedent.
Authority ranking: (1) U.S. and state constitutions, (2) federal statutes (supreme over conflicting state law), (3) state statutes, (4) administrative regulations, (5) case law/common law (stare decisis). Uniform laws such as the UCC become binding law only after a state legislature enacts them.
Common law (judge-made, built case-by-case through precedent) vs.\ statutory law (enacted by a legislature) --- the UCC is a statute (a uniform act adopted by states), not common law, even though it codifies commercial custom.
Students assume the UCC governs all contracts; it actually governs only contracts for the sale of goods (Article 2) and related transactions --- general/common-law rules still govern services, real estate, and employment contracts.
Constitution $arrow$ statutes $arrow$ regulations $arrow$ common law = hierarchy of authority.