From Drawers to Tap Pants

I originally started looking at historical changes in lingerie for the sexual energy the whole topic evokes->then I learned how much of a serious issue lingerie is. Seriousness arising out of discussions regarding why certain people wore certain things--the commercial, health and fashion considerations of every article. There is much concern that presentations be historically correct.
knowlesville.com offers a pictorial history from 1840-1940 while discussing briefly the efforts some women undertook to dress correctly.

Victorian and Edwardian women wore a lot of lingerie, and sometimes it's confusing what goes where and what it's called. Here's a helpful guide:

A Victorian woman started her marathon dressing session with a pair of drawers. Drawers are most often split (crotchless) and about knee length. Some drawers aren't split, and it makes you wonder how they worked, since they were under alll the other layers. Many times you'll see drawers refered to as bloomers, pantalets, or even pantaloons, which are really men's pants. Over her drawers, she would slip on a chemise which is a long sleeveless gown. A shorter version of a chemise is a camisole. Both the chemise and the camisole protected the skin from the corset, and vice versa. The next layer would be the corset. Over the corset would be worn a corset cover which protected the outer garments from the busk of the corset as well as hid the corset under sheerer garments. Sometimes it's hard to determine if a garment is a camisole or a corset cover, so we've grouped them together. Depending on the period, different types of hoops cages and bustles would then be added to give the outfit the shape that was currently in fashion. Next one or more petticoats were added to provide even more fullness under the skirt. Finally, after donning at least 5 layers of underwear, the Victorian woman was ready to put on her skirt and bodice.

After the Victorian and Edwardian periods many of these layers were simplified. As corsets became less structured and offered less support for the breasts, brassieres were introduced, and these later became bras. In the 1920s and 30s, cotton chemises gave way to silk and rayon slips & teddies, often cut on the bias. Drawers became tap pants, and then later panties.
Through out all of these periods, there were gowns and robes for sleeping and lounging.