American colonial clothing reflected the fashions of Europe. The silhouette of 1700s fashion was a conical bust over a full skirt. The upper body was shaped into an inverted cone shape with stays, the precursors of corsets. Poor women wore the simplest clothing, a shift or chemise covered by a "nightdress," which was a simple dress with gathered neckline and sleeves. Over that they might wear an apron or a gathered skirt. Wealthier women wore the shift and stays, a silk petticoat, and an overdress that was open in the front to show off the petticoat. Girls wore clothing that resembled their mothers' clothes.
Make a knee-length chemise, similar to a nightgown. Generally they had rectangular elbow-length sleeves, a scooped neck and were embroidered or decorated with lace or ribbon. To be authentic, the fabric would be linen or wool, but cotton will also work.
Make stays to achieve the authentic inverted cone shape with the breasts pushed up and the back flat. Because breasts were pushed up so high, the neckline often was covered with a lace kerchief or ruffle to provide extra modesty. Stays were stiffened with whalebone, wood or metal strips. They were worn over the shift or chemise.
Sew a petticoat out of a light fabric, such as silk or embroidered cotton. The petticoat should be very full, full-length and have a draw-string waist. Petticoats weren't considered to be underwear, instead they were meant to be seen and to provide a pretty contrast to the gown worn over them.
Make a gown with a tight bodice, tight elbow-length, ruffled sleeves and a gathered skirt, open in the front to reveal the petticoat. If you don't want to wear stays, make the bodice of the gown tight, and have the waist curve down to a point in the center front. Gowns were made in many colors, including red, yellow, purple and green, according to Longago.com. Ultra-respectable and very serious people wore black. Blue was worn by servants and children, and a reddish-brown was the color for farmers and other country people.
Wear a lace neckerchief, a triangular lace scarf, over the gown to cover the shoulders and chest. Wear Mary Jane shoes, as they resemble shoes worn by young women in Colonial times. Upper class women sometimes wore a stomacher, a stiff triangular piece pinned over the gown from the chest to the waist. It's purpose was to enhance the cone-shaped upper body, with smooth tight lines narrowing from the bust line to the waist. Middle class women and working women often wore aprons from the waist to the gown's hem. The apron might be very plain and utilitarian or lacy and delicate.