I just discovered that the Society of American Archivists has made back issues of their journal available for free online. Big whoop you say? While many of the articles are not terribly interesting for a genealogist, many are fascinating. For example, take this article on The Creation and Destruction of the 1890 Federal Census, by Robert Dorman. It provides an illuminating look into the political and social issues that shaped the way the 1890 census was conducted, stored, and lost. Did you know that at one point, a congressman suggested that ALL the censuses, back to 1790, were "antiquated" pieces of paper not worth the cost of storage?
I didn't know that, when the creation of a national archives was being discussed in the 1930's, there had been dozens of fires and floods that damaged records. The one causing the most public outrage, apparently, was a 1911 fire at the New York State Library -- I haven't done any New York Research, but this sounds like it was a real tragedy, destroying much of the records of the Dutch Colonial period.
Scary reading, indeed.