I have blogged in the past on my research on this subject. Documentation sometimes shows up in places that are unexpected. I was looking at Le Journal Amusant on-line.....
http://gallica.bnf.fr/ark:/12148/cb327966940/date.r=Journal+comique+et+illustr%C3%A9.langEN
http://gallica.bnf.fr/ark:/12148/cb327966940/date.r=Journal+comique+et+illustr%C3%A9.langEN
...at cartoons from the 1860s and found a small cartoon in a series of camp life at the training camp at Chalons in 1868. Click to enlarge
From GOOGLE Translation..the annoyed woman is telling the soldier, an orderly for an officer to just throw a letter on her bed and she will read it later.
The dutiful orderly replies that his lieutenant ordered him to hand it to her and await a reply.
It's clear that the woman wears her chemise tails under her drawers in this example. I have been looking for period documentation that this was the custom.
more to come......