Moby-Dick is what is called a "fluid text": there are several different versions of the book. The first American edition, published in November of 1851, contained typographical errors, along with other errors that Herman Melville later corrected himself. The first British edition, published that same year, included some of Melville's corrections and some valid ones of its own, but was also edited to remove bawdy and anti-monarchical passages, among other material thought objectionable. The first British edition also accidentally omitted the book's epilogue.
There is no known surviving manuscript of the book, and editors through the years have worked to reconstruct what Melville's original intentions for it may have been—and made their own corrections and abridgements along the way.
For this online version, I began with the text of the first American edition. As I was annotating it, I came across a few passages that were unclear because of known typos or errors. These, I altered to align with later editions that made more sense to me. The two most noticeable changes are to two historical names: "Cranmer's polytheistic ashes" was changed to "Wickliff's polytheistic ashes" in Chapter XXXV, and "Captain Butler of old" was changed to "Captain Church of old" in Chapter XLV. For an in-depth look at historical revisions to the book, see
Moby-Dick: A Longman Critical Edition (Pearson Longman, 2007), edited by John Bryant and Haskell Springer.