I'm a baaaaaad boy + slips vs. linings

I know, I know, I need another Forties dress pattern like I need another laugh line, but I saw those dropped yokes and thought, how cute (or in Forties-speak, what a smart frock!).  It's certainly not because I'm a big fan of Renee Haal, whoever she was.  It was one of those "best offer" eBay listings so I got it for $6.

I liked this one, too, but not $18's worth.

Cathy's wardrobe is starting to look a little like Ann Sheridan's and I think she's starting to resent it; Cathy's such a contemporary gal albeit a true style chameleon.  If all goes as planned she'll be out modeling my purple 1937 Hollywood pattern today, so expect a fashion show on Friday if not a photo in the Times.  I think we'll forgo the big lips this time around; yesterday's Joan Crawford video turned me off those big time.

But, readers, what I really wanted to talk about today is linings.  One of the things I've noticed sewing all these vintage dress patterns is how none of them (so far) have called for a lining.  My understanding -- and please correct me if I'm wrong, peeps -- is that back then (the Thirties and Forties) women wore slips and dresses were not lined.

That would explain the countless patterns like these:

I don't think women are wearing slips much anymore, right?  Most of the relatively contemporary dresses I see at the Salvation Army are lined.

So I'm wondering: is a lined dress something new?  When did women stop wearing slips (I know my mother did back in the day) or start wearing them less?  Other than something like a formal blazer or coat, most men's clothes I've owned are not lined.

I've read that lining a garment helps the fabric hang better and gives the garment a longer life.  Would this not also be true of a slip?  A slip makes sense since you can wash it separately.  And lining a garment is a huge hassle as far as I'm concerned; I've only done it a handful of times and hated it every time.  It's like sewing a second garment when you're still exhausted from the first!

So what's the story with slips and linings, ladies (and men who know more about slips and linings than I do)?  Is wearing a lined dress nicer than wearing an unlined dress with a slip?

Would you ever wear a slip with a lined dress?

Could there be a conspiracy between clothing manufacturers and dry cleaners to make you need to have your dress cleaned more often since it's lined and in direct contact with your skin?

Please lead me out of the as-yet-unlined darkness!