A basic understanding of the United States legal system is essential to knowing what to look for and where to find it. The legal system is actually three parallel systems–federal law, state law, and administrative law–operating under the authority of the US and state constitutions. The primary law of each system flows from four primary sources:
In order to research effectively, you must determine if the issue involves federal or state law and what type of primary law applies.
To determine what law applies, you can turn to secondary sources. This catch-all category of legal materials is essentially everything that is not primary law. Secondary sources are materials that explain, analyze, critique or help you find the law. Examples are
Many researchers recommend beginning with secondary sources because these helpful materials are a rich source of citations to the primary law.