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Researching the Law in the United States for LLM Students


The U.S. Constitution sets out the structure of the federal government, provides fundamental laws, and guarantees basic rights for citizens in the United States. 
Each state has its own state constitution. You can generally find a copy of a state constitution on the state legislature's website. 

You can also find annotated versions of the U.S. Constitution and state constitutions on Westlaw and Lexis Advance. Researching a section or clause of a constitution by using an annotated version is an efficient research strategy because the databases will provide relevant cases interpreting the Articles, sections, clauses, or amendments and will also link to various secondary sources discussing or analyzing the constitution. 

You can find an annotated version of the U.S. Constitution within the United States Code Annotated (on Westlaw) or within the United States Code Service (on Lexis Advance).

You can find annotated versions of state constitutions within the state codes on both databases. On the Westlaw homepage, click on "State Materials," then select the relevant state you are researching. On the Lexis Advance homepage, click on the "State" tab, then select the relevant state you are researching. 


Federal Statutes:

Federal statutes are laws enacted by Congress. These statutes are first published individually as slip laws, then compiled into session laws (in the U.S. Statutes at Large) in chronological order. The session laws are then codified (organized by topic) in the United States Code. The United States Code is the official version of the code and is published every six years (last published in 2012), but supplements are published each year. When a statute is cited in a case or article, you will typically see a citation to the U.S. Code (e.g., 18 U.S.C. § 371 or 17 U.S.C. § 109). 

  • The official, authenticated version of the United States Code is available on GPO FDSys (U.S. Government Printing Office's Federal Digital System): FDSys United States Code
  • To track the status of pending bills and to find recent legislative history materials, visit:
  • To find a session law, use the HeinOnline U.S. Statutes at Large collection. Note that HeinOnline also has older versions of the United States Code available in the HeinOnline United States Code collection.

There are two unofficial, yearly publications of the United States Code: United States Code Annotated (available on Westlaw) and United States Code Service (available on Lexis Advance). If you are trying to find cases interpreting a statute, use one of these resources because they contain case annotations. 

For information on how to conduct a federal legislative history (i.e., how to understand the intent behind a law) and how to access older legislative materials, please see our research guide on Researching Federal Legislative History

State Statutes:

State statutes are laws enacted by the state legislature. A state generally has the state code available on its state legislature website, but you can also access annotated state codes through Westlaw or Lexis Advance. On the Westlaw homepage, click on "State Materials," then select the relevant state you are researching. On the Lexis Advance homepage, click on the "State" tab, then select the relevant state you are researching. It is more efficient to conduct research using an annotated state code because the databases will identify relevant cases and secondary sources that cite your statute in the annotations to the code. 

In California, the preferred statutory compilations for citing statutes in court filings or law review articles are West's Annotated California Codes (available on Westlaw) or Deering's California Codes, Annotated (available on Lexis Advance). If you are researching the law of another state, check Bluebook Table 1 to identify the preferred statutory compilation. 


Publication Process:

A case is first published as a slip opinion, and then later published chronologically alongside other cases in a bound volume case reporter. Citations to cases are usually to the version of the case from a reporter, not to the slip opinion. Bluebook T1 provides guidance on the preferred reporters for citations.  

To illustrate this process, let's look at a Supreme Court case: United States v. Jones, 565 U.S. 400 (2012).  

  • Slip opinion: The Supreme Court decided this case on January 23, 2012, and a slip opinion was published on the U.S. Supreme Court's website that same day.
    • Click here to see the slip opinion from the U.S. Supreme Court's website. 
  • Official reporter version: The official reporter for Supreme Court cases is the United States Reports. HeinOnline has digital copies of the official reports within its U.S. Supreme Court Library collection.
    • Click here to see the official publication of the case in the United States Reports.
  • Unofficial reporter versions: There is a lag time of four or five years before a case is officially published in the United States Reports. In those years before it appears in the official reporter, you may see citations to the case to a version printed in an unofficial reporter. For Supreme Court cases, you likely will see citations to the Supreme Court Reporter (S. Ct.). This is a commercial unofficial reporter published by West. You can view a copy of the case as printed in this unofficial reporter on Westlaw.
    • Click here to see a copy of the case printed in the Supreme Court Reporter. Click on the PDF icon that indicates "Original Image" in the upper left corner of the screen to view the case as it appears in the print bound volume.

Parts of a Case:

U.S. Supreme Court cases are preceded by a syllabus. A syllabus outlines and summarizes the decision, but is not written by the Court. When citing a case, you should cite text from the opinion itself, not the syllabus. When you retrieve a copy of a case from Westlaw or Lexis Advance, you will also see headnotes before the start of the opinion. The headnotes are editorial content written by Westlaw and Lexis editors, not the judge, so do not cite these. 

For more information on case reporters and parts of a case, please view the following screencast videos prepared by librarians at the Robert Crown Law Library. 

Databases for Searching for Cases:

You can find the text of cases on various free or low-cost websites or databases, but the best databases to conduct case research are Westlaw and Lexis Advance. This is because both of these databases have reputable citators, which assist you in confirming the case is still "good law." A citator provides you with the subsequent history of the case as well as insight into how the case has been treated by other cases. Westlaw's citator is called KeyCite, while Lexis Advance's citator is called Shepard's. Before citing a case in a court filing or referring to it in court, make sure to KeyCite or Shepardize your case to ensure that it is still good law. 

Rules and Regulations

Statutes provide agencies with authority to issue regulations. An agency will issue a proposed rule, which is published in the Federal Register, and then the public can comment on the proposed rule. Comment periods are generally between 30-60 days, but vary in length. After the notice-and-comment period, the agency may publish a supplemental proposed rule for additional comments or may proceed with a final rule, also published in the Federal Register. The final rule is then codified (organized by subject) in the Code of Federal Regulations (C.F.R.). There are 50 subject matter titles in the Code of Federal Regulations, and each subject matter title is republished once a year.

The Code of Federal Regulations is available on U.S. GPO FDSys. You can also view annotated versions of the Code of Federal Regulations on Westlaw and Lexis Advance. 
To access the Federal Register and to view comments to proposed rules, use the following resources:

States agencies issue state regulations, and the state rulemaking process generally mirrors the federal rulemaking process. For example, in California, the California Code of Regulations is the codification of the rules and regulations issued by California State agencies (similar to the Code of Federal Regulations). The California Regulatory Notice Register contains notices of proposed regulations or regulatory changes (similar to the Federal Register). 


International agreements are another source of federal law in the United States. Treaties are international agreements that enter into force after two-thirds of the U.S. Senate gives its advice and consent. Executive agreements are international agreements brought into force on a constitutional basis other than with the advice and consent of the Senate (i.e., an agreement between the President of the United States and the head of government of another nation). Executive agreements are more informal and far more common than advice-and-consent treaties. Both treaties and executive agreements are binding under international law.

Official Sources of Treaties Where the United States Is a Party: 

  • U.S. Treaties and Other International Agreements Series (U.S.T.): for treaties and agreements that entered into force between 1950–1984 ("bound volume")
  • Treaties and Other International Acts Series (T.I.A.S.): for treaties and agreements that entered into force since 1945 ("slip" treaties)
  • U.S. Statutes at Large (Stat.): for treaties that entered into force prior to 1950
  • Senate Treaty Documents

Sources for Identifying the Status of U.S. Treaties:

Secondary Sources: Books, Treatises, and Journal Articles

Legal Databases:

Westlaw, Lexis Advance, and Bloomberg Law provide electronic access to a wide range of treatises and practice guides. Coverage varies depending on the publisher. You can also find law journal articles on Westlaw, Lexis Advance, and Bloomberg Law, but the HeinOnline Law Journal Library has the most comprehensive coverage of law journals, providing PDF copies of articles from over 2,200 law and law-related periodicals dating back to their date of inception.

SearchWorks (Library Catalog):

To find books and journal articles, type in the publication name into SearchWorks, our library catalog. For example, if you are looking for a copy of an article that was published in the Stanford Law Review, type in "Stanford Law Review" into SearchWorks instead of the title of the article. Our catalog will indicate whether the item is available through an electronic database by displaying a green "Online" button. Click on that button for links to databases that provide electronic access to this publication. 

Interlibrary Loan (ILL):

 If our library does not have a book or publication, we can try to obtain it for you by borrowing it from another library. Please submit an interlibrary loan request using our Interlibrary Loan Request Form. For more information about interlibrary loan, please click here

Additional Resources

Black's Law Dictionary: Black's Law Dictionary is the most widely used law dictionary in the United States and will assist you with defining legal terms used in primary law and secondary legal materials. 

Online Research Guides: Online research guides from our law library and other law libraries are free resources that will assist you with researching a wide range of topics. An easy way to find research guides is to conduct a Google search for "research guide" + [your topic]. For instance, you can conduct a search for copyright law research guide or administrative law research guide. It is a good idea to compare a few research guides on a particular topic because quality varies. You can also find the research guides prepared by the librarians at the Robert Crown Law Library here

Print Research Guides: Our library collects research guides in print that provide more in-depth coverage than online research guides. To find these research guides, conduct a search on SearchWorks. For state law research, the Eyles aisle in the second floor reading room contains a set of print research guides with each book pertaining to conducting legal research in a specific state (e.g., California Legal Research, Washington Legal Research, etc.).