The U.S. Constitution guides our whole country with principles for the structure of our legal system and how the three branches of government have authority to make and enforce laws. Legislatures and judges make laws, but they cannot conflict with the U. S. Constitution or the Constitutions of any state.
Federal and state legislatures create agencies such as the Internal Revenue Service and the Environmental Protection Agency. These agencies are overseen by the President or governors after they are created by the U. S. Congress or state legislatures. The agencies issue regulations which explain and expand the federal and state statutes. These regulations then become part of administrative law.
Federal and State Statutes
Statutes are laws passed by federal and state legislatures. As bills are passed into laws over time, they are written down into codes. Federal and state statutes are organized by subject matter.
Local governments like city councils and county boards pass ordinances which become zoning codes, health codes, building codes, and so on. These ordinances are then enforced and regulated by the local governments which create them.