Why is the most common date format in the US like `mm/dd/yyyy`, whereas in Europe (including the UK) it's more common to have `dd/mm/yyyy`?

Looking around, I found that [the US form is actually the more traditional Anglo-Saxon way](http://www.antimoon.com/forum/t1952.htm), but the British adapted to using the European form in the early 20th Century.

But I couldn't find a definitive discussion of the history of the different formats. Is it just conventional, or is there an official 'British date standard' (like with metric and imperial, for example).