I had supposed that the 'endless creations' of the 1700s were during the war with France, which would have been the late 1700s.

However, I have often heard of similar arbitrary cutoffs: there is the stereotype of the American settlers who 'came over on the Mayflower,' like arriving a decade later makes a vast difference when one is talking of centuries of history. (Personally, I like Will Rogers's comment, that his relatives 'met the boat!')