My wife and I have spent entire days sitting in university special collections copying documents using cameras where this is allowed. Usually, she turns the pages and I take the images. Most of the special collections libraries have a substantial charge for making copies and prohibit scanners, but we have found them open to allowing cameras. My interaction with the special collections libraries at different universities has brought home the importance of these collections to those doing genealogical research. Many researchers look for the names of their ancestors as if the names alone were some kind of magic talisman that was going to reveal all of their family history. Sadly, this is not the case. Genealogy is basically historical research and many times your effort to find your ancestors must be based on a general search of all of the possible historical documents in a particular area at a particular time.
University special collections departments are like black holes, sucking in all sorts of rare and interesting documents. Although geographic proximity is important, that is, the library should be in the same state where your ancestors lived, it is not always the case. One major collection about my Great-grandfather Henry Martin Tanner is in Salt Lake City, Utah at the University of Utah even though he lived his entire life in Arizona. In this case, the person who did all the research and donated the documents to the University of Utah lived in Utah at the time he died.
Since the special collections libraries are not very selective, you may need to research the catalogs of many libraries before finding the jackpot in one. This was reinforced to me when I began investigating the universities and colleges in North Carolina. There happen to be 16 major universities and a huge number of colleges. Every one of these has a library and the potential to be the host of records about your family if they lived in North Carolina.
Fortunately, most or nearly all of these libraries around the country have extensive catalogs of their holdings. In some cases, you may find extensive entries listing the documents in a particular collection. It is also a good idea to search in the WorldCat.org catalog for the names of your ancestors and the places where they lived. You never know what you will find until you start searching.
Here is a screenshot of one of the collections of documents I have donated to libraries. This one is from my Great-grandmother, Mary Ann Linton Morgan and contains the names of thousands of her relatives.
If you look carefully at the entry, you will see that the collection contains two linear feet of documents. That is thousands of pages of information about her family collected over her lifetime. Can you really assume that your relatives are not mentioned in such a collection that might exist in a library somewhere in the country where they lived?
Here is the same collection as found in the WorldCat.org catalog.
This is what the description says:
The Mary Ann Linton Morgan family papers contains genealogical information and pedigree charts compiled by Mary Ann Linton Morgan. Also included are letters from 1869, 1878. Old family trees of the Sutton family are included. A diary from 1924 is contained as well as the patriarchal blessing of Mary Ann Linton Morgan. In addition, there are two letters to the family of John Hamilton Morgan from Heber J. Grant. Missionary photographs from the 1930s in Tonga are included from an Elder Vincent. The collection contains documents from 1869-1990 but primarily consists of materials from circa 1930-1950.You might notice that some of the documents are not from her family at all. How would you ever know unless you search?