What Primary Legal Sources Can I Find on LII?

The Legal Information Institute (LII) at law.cornell.edu publishes free primary legal sources for U.S. federal and state law, plus selected international locators. You can use it to read the U.S. Constitution, the U.S. Code, the Code of Federal Regulations (C.F.R.), Supreme Court materials, federal rules, state statutes, and state regulations for all 50 states. The site states its mission as publishing law online for free and creating materials that help people understand law. The main limitation is that LII is a publisher and locator, not an official government publisher, so for filing or citation-critical work you should confirm the text against the official source.

Federal primary sources

LII's Legal Resources section organizes federal materials under "Primary Sources." The listed federal sources are:

• Constitution — the U.S. Constitution, with the Congressional Research Service's U.S. Constitution Annotated available as original content that includes recent Supreme Court decisions.
• U.S. Code — LII states the U.S. Code is up to date through the most recent version published by the Office of the Law Revision Counsel.
• C.F.R. — LII states the C.F.R. is up to date.
• Supreme Court — Supreme Court materials, including the LII Supreme Court Bulletin, which publishes case previews.
• Executive Orders
• Federal Rules — the federal rules of practice and procedure.
• U.C.C. — the Uniform Commercial Code.

What to check before relying on a federal text

Because LII republishes government material, treat it as a reading and research copy. If you are citing in a brief, filing, or exam answer, verify the section number and current text against the official government source (for example, the Office of the Law Revision Counsel for the U.S. Code). LII's own "What's New" notes are the best signal of currency: the U.S. Code and C.F.R. are described as up to date, but updates depend on the government's publication schedule.

State law and state regulations

LII publishes state regulations for all 50 U.S. states, in addition to state law. The Legal Resources section lists:

• State law
• State regulations
• State statutes by topic — a locator that groups state statutes by subject rather than by jurisdiction.

This makes LII useful when you know the topic but not which state's code to open, or when you need to compare how multiple states address the same subject. For a single state's current statute, the state's own legislature or code publisher remains the authoritative text.

Locators and finding tools

Beyond full texts, LII provides tools for locating law across jurisdictions:

If you have a popular name (for example, a named act) but not a citation, the Table of Popular Names is the faster entry point than browsing a code.

Original content for understanding the law

LII also publishes explanatory material alongside the primary texts:

• Wex Legal Encyclopedia — a legal dictionary and encyclopedia, with entries such as birthright citizenship, disenfranchisement, prediction market, and surveillance pricing.
• Congressional Research Service's U.S. Constitution Annotated — constitutional doctrine with recent Supreme Court updates.
• LII Supreme Court Bulletin — case previews.
• Introduction to Basic Legal Citation by Peter W. Martin — a citation guide.
• The Gender Justice Collection — topics including education rights and technology-facilitated gender-based violence, with resources for Colombia, the Philippines, and the United States.

These are secondary and explanatory, not primary law. Use them to orient yourself, then read the underlying text.

How to use LII effectively

1. Start from the Legal Resources list if you know the type of source (Constitution, U.S. Code, C.F.R., state law).
2. Use a locator (Table of Popular Names, State statutes by topic, World law) if you know the subject or common name but not the citation.
3. Read the primary text, then check the "What's New" notes to see whether that source has been updated recently.
4. Confirm against the official publisher before filing, citing, or relying on the text for a decision.

A practical example: if you need the federal regulation governing a specific agency practice, open the C.F.R. through LII to read and understand the provision, then verify the current text against the official eCFR or Federal Register before quoting it in a filing.

What LII is not

LII is not a government website and does not issue official texts. It also does not provide personalized legal advice. Its value is free access, cross-jurisdiction locators, and plain-language explanatory material — not official certification of any document.