Aw, now, why does this sort of thing always come up when my books are at work, and I'm home?
Regarding fall-front pants....to the best of my recollection, my Blue Book of Men's Tailoring, published in 1908, has a pattern for broad-fall pants, with a statement to the effect that, while they are no longer in fashion, any decent tailor needs to know how to make them, as many "older gentlemen" prefer to wear them. In 1908.....
I'll return with better documentation later in the week, I promise.
Also, just to stir the pot a little--my persona is a Swedish immigrant woman, and while my husband and I are 'city folks' with university educations, many Swedes were still wearing what we would think of as 'folk-costume' up until the 1960s, at least to church on Sundays. Most of the men's outfits would have fall-fronts--most were even knee-breeches.
Now, people being what they are, I'm sure even if the immigrants arrived in America with old-fashioned fall-front trousers or breeches, they probably changed them as soon as possible, in order to fit in better. But--it's possible that they could have made it out west.....
No, I don't have a scrap of documentation--immigrants don't seem to have had their pictures taken very often. So you won't be seeing Lars in knee-breeches at a shoot, though I might wear my folk-costume to a banquet sometime.
Stina