Pecksniffery is the quality of being a pecksniffian (who who affects high moral principles). The word comes to us via the gift of Charles Dickens' Martin Chuzzlewit, which features a character named Seth Pecksniff.
Yet while Merriam-Webster traces the first known use of pecksniffery to 1849, we can prove better. We encountered the word (whimsically illustrated, no less!) in Punch, Vol. X, 1846, p. 149. (We do what we can!)