In the movie Forrest Gump, actor Tom Hanks playing Forrest Gump says "Life is like a box of chocolates, you never know what your going to get".
In the archives world it can be said "Vertical files are like a box of chocolates, you never know what your going to get".
Vertical files or Subject files as they are sometimes called can be located in most state and local archives, historical society collections, genealogical society collections, libraries and in some museum collections. What exactly are vertical files?
Vertical files are a collection of documents and ephemera that are put in file folders which are then put in filing cabinets cataloged by surname or subject. These files could contain just about anything that can fit into a file folder. Most repositories will create an index by the title on each folder but most of the time what is inside of each folder is not cataloged. Vertical files are sometimes seen as a "catch all" for all those documents that don't really go anywhere else but should not be discarded.
Genealogists should be encouraged to ask the archive they are visiting if they have vertical files. These collections of records could be very valuable to your research and could contain that piece of information you have been searching for all these years. Some archives don't always advertise that they have such a collection of vertical files so it's important that the researcher ask the archivist about this collection specifically.
Usually you will have to request the files that you would like to look at and the archivist will retrieve them and bring them to you, sometimes only one or two files at a time. Then you will be allowed to go through what is contained in the file and make copies of what is important to you. Once you have finished with the file you give it back to the archivist who will then bring you any other files you have requested one or two at a time.
Please do not think that the archivist doesn't trust you in this process, they are required to carry out this process for everyone. Sadly, document theft is very prevalent in our archives, libraries and other repositories and so they are forced to institute rules on how records are to be handled by the patron.
Next time you are at your local archives or records repository, ask if they have vertical files "you never know what you are going to get".