An Essay Concerning Humane Understanding

No UK-versus-US or original-language precedence question: the London folio is the only original, and it was issued in December 1689 despite the 1690 date on the title — the normal printing convention for books appearing late in the year. The edition to name alongside it is the 1694 second (London: printed for Awnsham and John Churchill, and Samuel Manship; folio), which is collected in its own right because it carries the first appearance of Book II chapter 27, 'Of Identity and Diversity' — Locke's personal-identity chapter, added at William Molyneux's suggestion — together with an almost entirely rewritten chapter on power, the renumbering of the old chapters 27 to 31 as 28 to 32, new sectional summaries in the margins, and an analytical index. A copy wanted for the identity chapter is a 1694 book, not a 1690 one.