The purpose of underwear or 'drawers' was to protect the individual from the cold temperatures. Underwear was very simple and had little decorative design (if any at all).
Men's Underwear in 1850: men's underwear were ankle length, resembling loose fitting pants. Buttons or ties were used to fasten the underwear at the waist and at the ankles, to help prevent draughts. Men's underwear varied from being made of cotton, flannel or knitted wool, which determined how comfy and warm the underwear would be.
Women's Underwear in 1850: The underwear that women wore resembled the underwear that men wore. They were long enough to tie at the ankles. The early pairs of underwear for women were two separate sleeves for each leg and they would tie or use buttons to fasten at the waist and at the ankle. Of course this meant that there was a bare, exposed gap between the two leg coverings. Over the years women became experts at sewing the two pieces of fabric together to prevent having a gap. Women's underwear was typically made of cotton. Over the years the length of women's underwear also became shorter, to being tied just below the knee.Women refused to wear underwear when they first came about for obvious reasons. The main reason being it made it very difficult to use the privy because the underwear would have been worn under long skirts and/or several layers of petticoats.