"Panties," a lose garments with two legs, but not sewn together in the crotch. Used most by richer women. First worn during the Renaissance for function, but were also used as a sort of chastity device! They were described at the time as "Helping women keep clean and protecting them from the cold and they prevent the thighs being seen if they fall off a horse. These drawers also protect them against adventurous young men, because if they slip their hands under their skirts, they can't touch their skin at all" (The Great Book of Lingerie.)
I think we must also know that panties were not something that began to be used before late 19th century. The prudish Victorian age banned open-crotch undergarments, so women drawers had to switch to a side waist opening. Knickerbockers, (loose-fitting garments on the lower body) that joined up completely, started appearing in the 1850s, but most considered them very impractical, unhealthy, and unfashionable.
The general opinion was that it was harmful to cover the gender of women. Even impractical as the skirts were long and wide. Not so practical to start taking off both coats, petticoats and skirts just to make their needs!