US statutory law consists of the laws passed by the legislature.
    For the federal government, it is the acts passed by the United States Congress. [For a more information on how this is done, see Learn About the Legislative Process].  For states, it is the acts passed by their individual legislatures.

There are two kinds of acts:

1.  Public laws relate to the general public
2.  Private laws relate to specific institutions or individuals.

Regulatory, or administrative, law comes from the Executive Branch and its agencies, and independent regulatory agencies.
Agencies are given the authority to create administrative law through laws enacted by Congress and state legislatures. The law comes in the form of rules, regulations, procedures, orders, and decisions.
Agencies act in two roles:

1. in a legislative-like capacity when promulgating rules and regulations;
2. and in a judicial-like capacity when conducting hearings and issuing rulings and decisions on particular matters.

On the federal level, the process of administrative agency rule-making (from the initial notice to the promulgation of a final rule) is documented in two main titles of the Federal Register publication system: the Federal Register and the Code of Federal Regulations.
State agency rule-making follows the same process (check by individual states).