American Digest System

American Digest System in the United States

The American Digest System divides the law into major topic categories which are further divided into more specific subcategories – each subcategory is assigned a number. The number assigned to the subcategory is called a KeyNumber.

When a case is published, an attorney editor identifies each point of law contained in the case. These headnotes are assigned a KeyNumber which corresponds to a legal issue discussed in the case. All of the cases related to any KeyNumber are listed and briefly described in a research tool called a “digest.” In other words, a digest serves as an index of published case law from individual state courts, specialty courts like the Bankruptcy Courts, and the Federal Courts.

Case digests for American law, comprised of three different series: the Centennial Digest (cases up to 1896); the Decennial Digest (a number of sets covering either 10 or 5 years of cases, commencing in 1896); and the General Digest (volumes covering the period since the most recent Decennial Digest). The case digests are classified using the West Key number system. This publication is the US equivalent to the Canadian Abridgment Case Digests.

Practical Information

Maybe the most comprehensive digest (see it in U.S. law) series, covering all printed cases in all American jurisdictions from the year 1658.

West’s Digests bring together all the headnotes bearing the same key number. West publishes several Digests , each of which gathers headnotes from a different geographical or jurisdictional source. The American Digest series covers all the decisions published in all of West’s Reporters, and is therefore the master index to all of U.S. case law.

Volumes of the American Digest are issued regularly in a series called the General Digest , currently in its ninth series. Each new volume, several of which are issued per year, publishes the headnotes written in any of West’s reporters since the last volume. Every five years the General Digest is consolidated (it used be to consolidated every ten years, hence the title). The consolidated volumes are called Decennial Digests . The following table lists the present components of the American Digest System.

Years Covered / Digest / Number of Volumes

  • 1658 – 1896 / Century Digest / 50
  • 1897 – 1906 / First Decennial Digest / 25
  • 1907 – 1916 / Second Decennial Digest / 24
  • 1916 – 1926 / Third Decennial Digest / 29
  • 1926 – 1936 / Fourth Decennial Digest / 34
  • 1936 – 1946 / Fifth Decennial Digest / 52
  • 1946 – 1956 / Sixth Decennial Digest / 36
  • 1956 – 1966 / Seventh Decennial Digest / 38
  • 1966 – 1976 / Eighth Decennial Digest / 50
  • 1976 – 1981 / Ninth Decennial Digest Part 1 / 38
  • 1981 – 1986 / Ninth Decennial Digest Part 2 / 48
  • 1986 – 1991 / Tenth Decennial Digest Part 1 / 44
  • 1991 – 1996 / Tenth Decennial Digest, Part 2 / 64
  • 1996 – / General Digest, Ninth Series

How to use the Digest given the name of a case

  • Consult the “Table of Cases” volumes of the Decennial Digest series which covers the period of time in which the case was most likely decided. If it is a recent case, consult the “Table of Cases” volume of the General Digest.
  • Scan the alphabetical list of case names to find the case. Beside each case name is its citation. If the case has been judicially considered in a later case, its treatment (i.e., affirmed, reversed, or modified) is indicated and the citation for the considering case is given. Following this is the topic and key number of the main work under which a digest of the case can be found.

For very recent cases published after the latest General Digest was issued, check the “Cases Reported” tables in the weekly paperback issues of each of West’s individual reporter series (e.g ., West’s Atlantic Reporter , South Eastern Reporter , Supreme Court Reporter , etc .). The case digest will be found in the issue in which it was indexed.

How to use the Digest given the subject matter

Method One – Descriptive Word Method

  • Consult the “Descriptive Word Index” of the most appropriate Decennial Digest series of the General Digest.
  • Scan the list of descriptive words, looking for appropriate topics.
  • Each topic is written in bold capital letters. Sub-topics are listed underneath. The key number is indicated in lowercase bold letters.
  • Look the digest up under the topic and key number indicated.

Method Two – Topic Method

  • Consult the “List of Digest Topics” printed at the beginning of each volume of the Decennial Digest.
  • Scan the list of topics looking for the appropriate entry for your issue.
  • Turn to the appropriate topic in the main work. Topics are arranged alphabetically. At the beginning of each topic is a “scope note” which specifies what is in that topic. Key numbers are given for each topic provided.
  • Turn to the appropriate key number to find digests on point.

Method Three – Table of Cases

If you know the name of an American case applicable to your research, and would like to find other cases on that topic, you must first find the key number. This can be done in one of two ways:

  • Locate the known case in the West Reporter and take the key number from the appropriate headnote OR use the Table of Cases, which will give you the key number of the case.
  • Look up the key number in the Digests to find other cases on the same topic.

Key numbers normally allow you to search for cases on a particular topic in any edition of the Decennial Digests. However, when issuing a new series of the Digest , in order to incorporate revisions to and expansions of the law, the publishers are sometimes required to revise the key numbering for certain titles. If your key number does not lead you to the appropriate sub-topic from previous editions of the Decennial Digest , it may be because the key numbering system for that topic has been revised. If this is the case, you will find a table of concordance at the beginning of the appropriate title in the current Decennial Digest .

Finding Key Numbers in Recent Volumes of the General Digest

Checking each volume of the current General Digests for new cases reported under your key number would be a time-consuming process. As a result, in every 10th volume of the General Digests , after the digests themselves, is a consolidated Table of Key Numbers. This Table covers the previous ten volumes of the General Digests indicating which volumes report cases under a given key number. To determine which volumes of the General Digest refer to a given key number:

  • Check the Consolidated Table of Key Numbers in the 10th volume of every General Digest.
  • Check the Table of Key Numbers in the most recent volumes of the General Digest which cover the volumes issued since the last Consolidated Table of Key Numbers from the last 10th volume.


The American Digest system is tied in with the national reporter system (read more) . It is broken down as follows: The bound volumes of the General Digest, cumulated about every four months, are followed by monthly pamphlets and by the weekly advance sheets of the reporters. The Decennials, as their names imply, are cumulated every 10 years and supersede the General Digest for that period. The digest covers approximately 500 main topics, arranged alphabetically.

The Century and Decennials are broken down alphabetically, each volume containing certain main topics. Thus, Volume 19 of the Fourth Decennial Digest, “Judgment to Kidnapping,” contains a reference to each case published from 1926 to 1936 on the topics of Judgment, Judicial Sales, Jury, Justice of the Peace, and Kidnapping. Each volume of the General Digest Series contains a reference to all the cases on every topic published during the period covered by that particular volume. Thus, each volume of the General Digest, Third Series, contains the topic Judgment.

A detailed fact index constitutes part of the American Digest System. The index is contained in several volumes, with a binding differing from that on the digests, entitled descriptive word index (in U.S. law). The descriptive words are listed in black type in alphabetical order. Different situations involving the fact element are listed in lighter type and refer to the place in the digest where cases in point may be found. The reference is by means of topic and key number. An analysis precedes each main topic. The digests of cases are grouped according to the point of law involved, and each point is given a key number. The key numbers in the First Decennial are preceded by the section symbol (§) instead of the key symbol, but the numbers correspond. The Century section numbers do not correspond to the key numbers but may be translated into key numbers (see below).

How to use the digest system

1. The first step in finding the authorities through the digest system is to get the key number. There are three methods of getting the key number: (a) If at least one case in point is already known, from the key numbers in the headnotes in the reporters, which correspond to the key numbers in the digests,

(b) From the Descriptive Word Index.

(c) From the analysis that precedes each topic. 2. The search may be started with any of the Decennials or with the General Digest and then worked forward and backward. 3. To avoid unnecessary research, use the cumulative tables of key numbers, which are paper pamphlets published in conjunction with the General Digest. These pamphlets list the topics in alphabetical order and list the key numbers under each topic. On a line with each key number are the numbers of the volumes of the General Digest in which reference is made to cases having that key number. 4. Continue the search for the key number through the monthly digests that are in pamphlet form and through the digests in the reporter advance sheets published subsequent to the latest monthly digest. 5. The second Decennial refers to the volume, topic, and section number in the Century, if there is a case in point referred to in the Century. If there is no reference, there are no cases in point digested in Century.

Table of cases

If the name of a case is known, find where it is reported from the tables of cases. The last five volumes of the First Decennial (Volumes 2125) cover the cases digested in the Century and in the First Decennial. The last volumes of the Second, of the Third, and of the Fourth Decennials are tables of cases. The back of each volume of the General Digest contains a table of cases. Since each unit of the American Digest System covers a particular period, the search is narrowed if the decade in which the case was decided is known.

(Revised by Ann De Vries)

What is American Digest System?

For a meaning of it, read American Digest System in the Legal Dictionary here. Browse and search more U.S. and international free legal definitions and legal terms related to American Digest System.

See Also

  • American Law Reports (ALR)
  • American Law Reports – Federal
  • American Jurisprudence (encyclopedia)
  • American Legal Systems: A Resource and Reference Guide
  • Jurisdiction in American law
  • West Key Numbers
  • West Headnotes

American Digest System in the Context of Law Research

The Thurgood Marshall School of Law Library defined briefly American Digest System as: An index of legal propositions showing which cases support each proposition covering all American courts of last resort, state and federal , from 1658 to present. Digests consist of series of paragraphs, arranged by topic, that provide brief abstracts (or digests) of opinions rendered by the courts. To be used only as a finding tool and should not be relied upon as an authority of any kind.Legal research resources, including American Digest System, help to identify the law that governs an activity and to find materials that explain that law.

American Digest System: Open and Free Legal Research of US Law

Federal Primary Materials

The U.S. federal government system consists of executive, legislative, and judicial branches, each of which creates information that can be the subject of legal research about American Digest System. This part provides references, in relation to American Digest System, to the legislative process, the federal judiciary, and the primary sources of federal law (cases, statutes, and regulations).

Federal primary materials about American Digest System by content types:

Laws and Regulations

US Constitution
Federal Statutory Codes and Legislation

Federal Case Law and Court Materials

U.S. Courts of Appeals
United States courts of appeals, inclouding bankruptcy courts and bankcruptcy appellate panels:

Federal Administrative Materials and Resources

Presidential Materials

Materials that emanate from the President’s lawmaking function include executive orders for officers in departments and agencies and proclamations for announcing ceremonial or commemorative policies. Presidential materials available include:

Executive Materials

Federal Legislative History Materials

Legislative history traces the legislative process of a particular bill (about American Digest System and other subjects) for the main purpose of determining the legislators’ intent behind the enactment of a law to explain or clarify ambiguities in the language or the perceived meaning of that law (about American Digest System or other topics), or locating the current status of a bill and monitoring its progress.

State Administrative Materials and Resources

State regulations are rules and procedures promulgated by state agencies (which may apply to American Digest System and other topics); they are a binding source of law. In addition to promulgating regulations, state administrative boards and agencies often have judicial or quasi-judicial authority and may issue administrative decisions affecting American Digest System. Finding these decisions can be challenging. In many cases, researchers about American Digest System should check state agency web sites for their regulations, decisions, forms, and other information of interest.

State rules and regulations are found in codes of regulations and administrative codes (official compilation of all rules and regulations, organized by subject matter). Search here:

State opinions of the Attorney General (official written advisory opinions on issues of state law related to American Digest System when formerly requested by a designated government officer):

Tools and Forms

Law in Other Regions

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