Images in the NCDHC collection are assigned tags that aid the researcher in identification. Almost anything can be tagged, from fences, to post offices, to lawyers. But I learned pretty quickly that the digital archivist cannot just assign tags as they please, there is a set of standardized tags already in use by the Library of Congress, called the Thesaurus of Graphic Materials (TGM). This thesaurus allows you to search for a word you may want to use, such as “cows,” for example, and gives you the scope of the term, whether or not to use a different term, related terms, broader terms, and narrower terms. Instead of “cows” you could use “cattle” or “livestock” as a broader term. Or, you could use “dairy cows.” Say you have an image of slaves becoming emancipated, so you want to use the term “emancipation.” The TGM will tell you not to use “emancipation,” but instead, use “liberty.” All images in the NCDHC are assigned such tags, and can be used to browse on the website by either alphabetical order, or frequency.