By a curious coincidence, I just noticed that the earliest surviving entries in the LCSH Subjects files were created on January 27th, 1986. This date would have been the first Monday after the ALA Midwinter conference (Jan 18th-22nd ,1986).
From the time stamps, it seems as if the system became live for new entries on this date. Older entries weren’t added until Feb 11th.
Less than half of these converted entries have had their references evaluated. This is suggestive.
Reference evaluation (008/29)
|b (Not Evaluated)||46,387||39%|
|n (No References)||27,320||23%|
[LCSH 150s, established, as obtained from authorities.loc.gov of December 2006]
The oldest surviving record, for “Grouper fisheries”, was assigned LCCN “sh 86000005″.
You should have seen the ones that got away.