The good old O.E.D.

I've been reading The Professor and the Madman by Simon Winchester (no relation).  The Oxford English Dictionary took 70 years to complete!  And it was spearheaded by some of the most eccentric scholars I've ever heard tell of.

Dr. W.C. Minor was a surgeon who went insane following his service in the US Civil War, murdered a man in London, and was confined for the rest of his life in an English asylum.  He was also perhaps the single greatest volunteer contributor to the Dictionary.

Professor James Murray was an autodidact (hah!) who spoke dozens of languages and spearheaded the renewal of the OED project after its first stutters.

Earlier English dictionaries were in general the work of a single man and varied in length, vocabulary selection, organization, and general helpfulness.  There were popular pamphlets (!) explaining the use of various "difficult" words, intended to make your diction suitable for discourse with academia, nobility, and the clergy.  The best available general dictionary before the OED was compiled by Samuel Johnson and published in 1755.  It was serviceable (allegedly "charming" also) but not particularly complete or objective. (Not its stated aims anyway, so whatever, right?)

Professor Murray took on the OED in 1878, and the first edition was published in 1921; it ran 12 (!) volumes and had over 400,000 entries.  Part of the mission of the creators of the OED was in express opposition to organizations such as L'Académie française, which sought to "fix" the form of the French language by strictly setting out what was and was not French (as it still does, in fact).  In contrast, the OED was to be a neutral POV recording of English "as she was," a mere historical record of the actual usage of the words.

Also, The Professor and the Madman is surprisingly entertaining for a book about a dictionary.  I highly recommend it.