Undergarments: Combination

my plan as of right now is to make a combination opposed to doing a chemise and drawers, as combinations we're introduced in the 1870's I'm well within the correct time period. I've used combinations before in different theatrical productions, both as an actress and as a part of the wardrobe team. I like them because it's one less thing you have to worry about, they literally area 'combination' of a chemise and drawers, this mean you only have one undergarment to find, wear, and wash. I also like them because their sizes are fairly universal, the neckline, and waist are drawstring meaning that they can accommodate many forms and typically the inseam is nearly completely open to allow for ease when going to the bathroom. Here's an example of the split in the middle

Here are some pictures of combinations from a bit later in the century

I've been reading some bits and bobs that say that the petticoat was worn under the corset later in the century, I just don't know what constitutes as later... :( need to find that out