Statutes are laws written and enacted by a government's legislative branch. Most statutes begin as bills.
At the Federal level, each statute is published in three versions. The first version is called a slip law, which is the statute by itself on a single sheet or in pamphlet form. When a slip law is published, it is assigned a Public Law Number to identify it. The Public Law Number (e.g., Pub.L. No. 112-25) consists of two parts: the first number represents the number of the Congress that passed the law, and the second number represents the chronological order in which the law was passed. In the above example, we have the 25th law passed by the 112th Congress. Slip laws/Public Laws are available through the Library of Congress's Congress.gov site.
Next, the statute is published as a session law. Session laws are the slip laws bound chronologically by Congressional session. (Each Congress lasts two years and is divided into two sessions). U.S. Statutes at Large is the official publication of Federal session laws.
It is often difficult to research a statute using the first two forms. In the final statute version, the code, laws are codified (placed in a subject arrangement). This final statute version is usually the most helpful. The official subject codification (published by the government) is the United States Code (U.S.C.). U.S.C. is broken down into 53 subject Titles, with each Title covering a major subject area, such as Labor, Transportation, or Education. Title 20 of the U.S.C. is Education. This version of the U.S. Code includes a Popular Name Tool (to find, for example, the "No Child Left Behind Act of 2001"). An alternate version is also available.
Unofficial versions of the code, such as The United States Code Annotated, are commercially produced and provide additional notes, histories, and case references.
Missouri law follows a similar pattern as that found in federal statutory law. Laws are first published in a chronological order and later codified into a subject arrangement. Annotated versions of the state code offer additional notes. Missouri statutes are codified in Missouri Revised Statutes; the annotated version is Vernon's Annotated Missouri Statutes.
In addition to the sources listed below, you can find federal and state statutes in LexisNexis. Refer to the explanation at the bottom of this page.