On 23 Nov 2011 10:24:53 Leo Goodstadt wrote:

For "acknowledgment" / "acknowledgement": both spellings started out in the 16th c. but the first form historically was found more in the US. Citations from the 19th and 20th c show that both variants are found on both sides of the Atlantic (e.g. the short form in the UK in Dickens, Bronte, Macaulay) though the long form seems to predominate in the 20c only in U.K. newspapers.

I too appreciate the clarification--- guess I didn't understand this quite as well as I thought. In the US, "acknowledgement" does seem to correlate frequently with a casual attitude toward spelling, but it looks like I need to broaden my horizons a bit.