An 1830s Petticoat.
Wearing this dress meant slapping this thing on every day:
I KNOW, RIGHT?
First of all, this thing went on after you put on your shift (or chemise, in my tortured parlance), and beneath the waistband you can see the corset, which your internal organs probably just LOVED.
(ETA: I seriously cannot tell if this is a corded corset with the petticoat on top and some unholy undersleeves attached, or if this is a corded bodice with sleeves that went under the petticoat, and had a corset on top. I'm hoping it's the corset with the busk and then the petticoat waistband going over, because heaven bless that woman if she had something laced up OVER this shit.)
Now then! The horizontal lines in the skirt are pieces of rope shoved through channels sewn into the petticoat. Later, these would turn into hoops, which is nice for ladies, since I can only imagine what it feels like to drag, oh, fifty yards of rope with you wherever you go? Maybe more; the circumference of the skirt is probably five to six feet, and there are how many channels in that thing? (Uh, P.S., how hilarious was it that people claimed women were the weaker sex? Just saying.)
Below left, a close up of the the UFO sleeves, which are wired for horizontal support, since you had another yard of fabric in each dress sleeve. (Seriously, the 1830s just could not have been uglier. I'm not fan of the 1860s superhoops or anything, but at least by then they had stopped sticking hot air balloons on their shoulders.)
Below right, the busk! At this point in history they were made of wood, bone, or ivory, and you basically shoved it into your corset as a front spine to keep you from collapsing under the weight of your own clothes. Have fun!
Heaven knows the clothing of the 1830s would drive me up the wall. If I had to wear it, I too would be riding around the countryside with my rifle shooting anyone who looked remotely comfortable in their clothes. So, you know, point to Isabelle.