- Statutory law is written by legislative bodies, e.g., Congress and state legislatures.
- Case law is that established by courts, e.g. common law, and interpretation of statutes and constitutions.
- Regulations are laws written by agencies, e.g. Environmental Protection Agency.
Federal, state, and local governments create laws for differing and sometimes overlapping arenas.
Use secondary sources to discover what laws might relate to your topic. Laws change over time, so match secondary sources to your desired time frame.