Once upon a time, there was no National Union Catalog, that is, a catalog showing the holdings of several libraries. If people using one library wanted to know what another library held, they had to find a catalog for that library, which usually meant going there or contacting a librarian by mail or telephone. Some libraries (the New York Public Library comes to mind) actually did issue books of photographic reproductions of their card catalogs from time to time, which other libraries held in their reference collections. Most libraries did not.
In 1901, the Library of Congress began to compile the National Union Catalog. At the time, the card catalog was the latest and greatest technology for compiling library catalogs, and remained so for most of the twentieth century. The only way to compile a union catalog was to photograph catalog cards and compile them in book form. Of course, the books became obsolete as soon as they left the printer. After all, libraries acquire new books and discard old, useless ones continually.
Therefore, the Library of Congress issued the National Union Catalog every month and then accumulated it quarterly, annually, and multi-annually. Five-year cumulative volumes served vitally important purposes, especially in facilitating inter-library loan. Libraries usually kept them in the reference section rather than in the inter-library loan office. Scholars used it, too.
In the 1960s, the library world decided to accumulate references to all pre-1956 imprints, as held by participating libraries, in a single alphabetical listing. The first volume appeared in 1968. The National Union Catalog Pre-1956 Imprints was completed, with volume 754, after 14 years of work. That’s longer than it took to build the Brooklyn Bridge. It cost more than some major library buildings of the time. The Library of Congress held a symposium to celebrate completion of this massive achievement in 1981, but otherwise it seems to have passed unnoticed
The entire set took about 130 feet of shelf space for any library that subscribed. Most American academic and large public libraries did. It also found a home in other libraries all over the world. Surely the National Union Catalog Pre-1956 Imprints is and will forever remain the largest publishing project in world history.
At about the same time, however, a library utility called OCLC (and competitors that it has since acquired) was building an electronic database that soon revolutionized inter-library loan. As WorldCat, the entire OCLC database (which grows daily) is freely available to the public. I have written about WorldCat elsewhere.
Although a significant number of the titles in National Union Catalog Pre-1956 Imprints have not yet been added to OCLC, that massive set has become less and less important to most libraries with each passing year. Many have already discarded their sets to make room for more heavily used materials.
So what’s a library supposed to do with gigantic set of huge books if fewer people use them all the time? A university library in Aarhus, Denmark decided to make a Christmas tree with their National Union Catalog in 2006. A student took the picture below and mounted it on Flickr.
That picture made the rounds of the Internet and inspired more than one other Christmas tree made of books, not necessarily the National Union Catalog. Here are two of a series of pictures of the construction of the Chrstmas tree made from the National Union Catalog at the Hannon Library of Loyola Marymount University in Los Angeles.
