I know, I know — to keep this site on the first page of Google, I should probably confine my remarks solely to double-breasted suits. If I stray too far off the path, I’ll plummet to page 32 again and I’ll never make any money off of this site.
“Suit” is usually taken to mean jacket, trousers (and until relatively recently vest/waistcoat) cut from the same cloth. An indeed it does. But when a man dressed, he did not always wear a suit: a suit was reserved for occasions of middling formality, while the odd jacket and trousers prevailed for less and more formal occasions.
Well into the twentieth century, heads of state, high-ranking ministers, and diplomats commonly wore morning dress during the day time, or the slightly less-formal stroller, along with top hats. This replaced the earlier double-breasted frock coat. Both morning coat and frock coat were worn with non-matching vest and trousers. While the coat was black and the waistcoat white or gray, the trousers were usually a charcoal gray, often with a slight stripe. Matching trousers were worn with evening dress, but the vest was usually white. Wearing your “suit,” sensu stricto, to the opera would result in your being politely turned away at the door.
But the odd jacket and trousers combination was not the exclusive province of the upper classes. I have pictures of a great-great uncle together with my great-grandfather and great-grandmother and her sister at a racetrack on their day off. This great-great uncle was a relatively poor immigrant to the United States, he worked, by all accounts nearly sixty hours a week running his small Midwestern grocery store. At work, he probably wore stout trousers of wool worsted, a shirt and maybe a vest and of course a cotton apron. But on his days off, he wore a dark (probably blue) jacket and light contrasting trousers, accessorized with a straw boater and a somewhat gaudy gold cigarette case. My great-grandfather is dressed in a less ostentatious dark suit and bowler hat. Both their costumes, for them probably close to their best attire, imitated the leisure clothing of the upper classes.
Another picture from the 1930s depicts my grandfather’s graduation from his primary boarding school; the uniform for summer seems to have consisted of a blue double-breasted blazer and flannels of white (or very light gray) summer flannel, white shoes and dark rep tie. The odd jacket and trouser combination was not uncommon, especially as trousers must be replaced more frequently than jackets, and it will be impossible to match a replacement pair exactly unless you still have the original bolt of cloth.
Our modern uniform of suit (usually black) is really not that formal, and it’s a bit stuffy when you consider all of the different subtle combinations of jacket, tie, waistcoat (or sweater) and shirt one was permitted in more “formal” times when “casual” meant “sportcoat and tie.” You could even liven up a drab outfit with argyle socks, or some interesting color like “heliotrope,” if Evely Waugh novels are any guide. Today, black or charcoal suit with no tie, or a blue blazer and jeans with no tie, seem to constitute casual dress.
A navy blazer and white wool flannel (or cotton? or linen? or jute?) will invite Thurston Howell impressions at most modern summertime parties, but it wasn’t that long ago that this was considered a cool and relaxed alternative to a suit. These fabrics are cooler than denim, and much smarter-looking. That’s why Mr. Howell wore such an outfit for his three-hour tour in the tropics. But the rise of climate-controlled everything has made people less cognizant of what they wear in warm or cold weather, and perhaps global warming has made all but the barest of coverings unbearable during the summer.
But that explains neither the decline of double-breasted jackets in general, even in temperate climes. Double-breasted has actually been trending higher of late, but jacket-wearing in general is still at abnormal lows. Men (and increasingly women) still slap on ill-fitting, cheaply made mass-manufactured two-piece suits with trousers for weddings and funerals. Despite the relative decline of the tailored suit, it remains de rigeur for certain occasions. It is the odd jacket and trousers, which used to mark the high and low ends of formality, which has all but disappeared.
We probably owe this to the general decline of jacket wearing for manual and non-manual labor (many workmen in former times wore mass-producted tailored clothing) has made any jacket at all seem too constricting, and thus unsuitable for casual dress. Your bus driver probably wears a starched shirt year-round, and so does your local policeman (or woman). In an earlier era, they would have worn winter or summer uniform jackets on all but the hottest days of the year. (And while I’ve never seen a double-breasted bus driver’s jacket, they were very common for policemen). It is to this general decline that we must assign blame for historically low production of both the double-breasted suit and the double-breasted jacket, even while their relative share of a shrinking tailored clothing market has been increasing.