Clothing has evolved over time. These threads talk about the development of the suit - the important takeaway is that black tie uniform, which we think of today as very formal, was actually considered informal to the point of being inappropriate for dinnerwear, in the early 20th century (The show Downton Abbey addresses this in Season 1, I believe, to throw in a fun pop culture factoid).

So when you see someone in a black tie and a jacket in a photo dating to 1905, they're actually not dressed formally according to the standards of that period.

Additionally, back in the day, photography was a far less ubiquitous technology. Getting your photo taken had less in common with today's mindless tapping-a-button-on-your-camera and more in common with going to get a portrait made - it was infrequent enough for most people that you'd want to dress up in nice clothes for it.

They weren't dressed formally. They were wearing suits made of tweed and other hard-wearing rougher fabrics, and the way that their clothes fit was often a dead giveaway of their non-upper class status.

It's only the modern trend into different styles of clothing that has mashed "suits" into one category that goes from tweed suits, which coupled with the brogues that gent is wearing, are actually only meant for country wear on an estate, and suitable for hunting, to black tie, which is actually known as "semi-formal", and white tie, which is true "formal" wear.

This new concept of a "suit" being classy is really just overlapping dozens of different levels of formality of the time that frankly have decidedly different levels of durability, utility and appropriateness for particular occasions.

Now someone wouldn't think anything of wearing a tuxedo for a daytime wedding, but in the past this would have been abhorrent, as a tuxedo was strictly evening wear, and daytime formal dress consisted of morning dress.

The point being, those people you see in old photos mostly weren't dressed "formally" by the standard of the day. It's only a modern unsophistication that leads some of us to believe that all suits are the same.

One should note that the working class never really dressed what you call formally.

Workers at Gävle wharf, 1929.

Note how they are wearing caps rather than hats, coarse shirts or jackets. No ties or suits.

US workers sometimes in the 50s.

You can note the caps again, and the same style of clothing - coarse shirts or jackets, no suits anywhere.

So I've gathered through this thread that even my finest custom-tailored suit seems woefully casual compared to what was considered formal from the 40's back. What did people wear to be comfortable, when they didn't need to look good? Lets say a casual errand run? What's the story behind this guy's attire: casual guy; a person attributed to being a time traveler because of his conspicuously comfortable garb? I just can't imagine being so uncomfortable, but sharp looking all the time.

Is part of the issue that most of what we think of as 'the style' in history - i.e. in the 1870s, women wore bustles - refers to what a fashionable upper class person wore? Is perhaps some of the issue just that media representations of ourselves today involve more ordinary people, who would perhaps have not been so formally dressed back then, and who are underrepresented in novels and historical accounts? I guess what I'm getting at is, while I know that if I read a mid-19th century novel, or even up to the 1940s, most everyone dresses for dinner, would that also have been the case for the cook, or the farmer and his wife? Or were their standards have been much more casual? Did men that wore the first jeans to work also wear them to dinner?