I am now wondering whether the American style of date came from Ireland. I have just been looking at an Irish Will Register which gives a date in the form "11mo 30 1876". I don't recall seeing anything like that before.
I once had a boss who decided to adopt dates as yy-mm-dd, following the Scandinavian idea, until someone replied to him along the lines of "Thank you for your letter of the 81st May 1921", after which he quietly ditched the idea.
All these Ancestry problems deserve a deluge of complaints. (They will not be reading this useful discussion.) This year, in a Society of Genealogists newsletter I came across the following in a list of recent additions to Ancestry. "The [1930s] one-quarter-inch scale map offers greater details of cities and villages, roads, railroads, and topographical information than the one-inch scale maps previously produced by the Ordnance Survey."
I wrote to them saying: "... that statement... must have been written by someone who has no understanding of map scales. A quarter-inch scale has detail approximating to a road atlas... the area of a map sheet is one-sixteenth of the equivalent sheets at one-inch scale.
"If people need a larger scale at that date, the OS was producing a six-inch to the mile scale or the 1:2500 scale. Both of these huge series have been uploaded by the National Library of Scotland on an excellent site so you don't need to bother... Also, we do not have any railroads in Britain."
Of course, there was no response!