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ARC Tutorials

Tutorial 6 - Hierarchy

This tutorial will take you through the steps you need to follow to navigate the Hierarchy of a set of archival descriptions in ARC.

You may find it easier to print this tutorial out and follow the steps on a paper copy. If you prefer, you can open a second browser window using the url and switch between windows to try the steps for yourself.

In order to describe the staggering amount of NARA's holdings, ARC primarily provides information about groups of related archival materials that share certain characteristics or traits. If time and resources allow, ARC may also include information about specific items, such as a photograph, letter, report, map or film.

NARA's largest groupings of materials are Record Groups and Collections. Record Groups generally include records from one Federal agency. Collections are usually comprised of donated materials from a single person, family, or organization. ARC descriptions of Record Groups and Collections provide high-level information shared by the entire grouping.

The next grouping level, at which the large majority of NARA's holdings are described, is called a Series. This grouping is similar to filing systems that may be found in any business or even in your own personal papers. Materials in a series were originally filed together because they resulted from a specific activity or are related in some other way. For example, a series might include someone's personal correspondence or include all case files relating to criminal activity in a particular court district.

The next ARC grouping level may be a File Unit or an Item. For some Series, the materials were originally filed together in groups because they share specific characteristics, for example all correspondence with one individual, or a court case file. A File Unit can consist of any number of individual folders.

Where possible, ARC also provides descriptions of Items, which are single documents, such as a letter, report, photograph, map, or film. Items may be grouped within File Units or filed individually within a Series.

These groupings form a hierarchy of descriptions within ARC:

ARC data model showing hierarchy of materials

ARC allows you to search for and find information at any level within a hierarchy, but ARC also allows you to learn more about the holdings by linking up and down within a hierarchy or searching for materials within a single grouping.

In this tutorial, we are going to find an interesting item, then find the related series and finally search within that series for other items we might be interested in.


  1. Start by searching for woman suffrage in the Archival Descriptions Search. Click on the Search button to start the search.

Archival Descriptions search on woman suffrage


  1. From your results, find the archival description with the title " Woman suffrage Headquarters [Congressional Union for Woman Suffrage], Washington . . ., 07/1917".

Hit #3 for Woman suffrage Headquarters [Congressional Union for Woman Suffrage], Washington

Click on the title to open the detailed description screen.

archival description result 3 detail showing hierarchy tab


  1. To see the hierarchy, just click on the Hierarchy tab.

The Hierarchy tab shows you the archival description in relation to higher level groupings within the ARC hierarchy.

hierarchy tab

Our original archival description was for an Item. Here you can see that item is filed within a Series which is part of a Record Group.

The Record Group is the highest level, then the Series, then the File Unit or ItemItems are the smallest unit described in ARC. You can view the relationships between the different levels of a hierarchy by looking at the indentations.

You can visualize a Record Group or Collection as a file cabinet, a Series as a drawer in that cabinet, a File Unit as a file folder, and an Item as a page within that folder.


  1. We are now going to look at the Series that this item is a part of.

First, click on the Details tab of the Item description, scroll down as needed, and click on the Part of: Series... link.

details showing 'Part of'

This will take you to the archival description of that Series.


  1. Scroll to see " Includes: 329 items described in ARC". As you can see there is an option that will allow you to limit your search to only Items from this Series. Click on the Search within this Series link.

Details showing 'Includes' and 'Search Within this Series' button

You will then see a new search screen.

'search within' search screen

Although the screen looks familiar, note that you are no longer searching all of ARC, but rather only a sub-set of records - just the descriptions for Items filed within the previously viewed Series.


  1. Enter the search terms officers and click on the Search button.

'search within' search page showing search term for officers

Your search results will show all the Item descriptions within this series that match the "officers" search term.

'search within' results with 11 hits


  1. To return to a basic search of all of ARC, return to the search screen and select Remove 'Search within' filter.

'Search within' search screen with 'Remove Search within' button highlighted


In this tutorial, we've shown how you can view the hierarchy of a single archival description. However, you can also view the hierarchy of a complete set of results by selecting the Hierarchy tab when viewing the results of an Archival Descriptions search. It will show all of the archival descriptions in the results and their higher level groupings. The following screen shot shows an example of this:

hierarchy of all results

Use the hierarchy to find out what is related to any archival description you find interesting.

You have now completed the ARC Tutorials.

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