There seems to be less dramatic change in the style of the wardrobe of the fashionable woman in the eighteenth century, than in the nineteenth, certainly in the essential types of dress. All dresses fitted a pattern, being ankle or floor length, with elbow length sleeves and a squared neckline, sometime with a short train, and with the skirt worn either closed, or open to show a decorative skirt or "petticoat". Around 1700, a gown known as a mantua was popular for most social occasions, comprising a long straight silhouette incorporating a short train, orginally worn down, and later looped up. By the middle of the century, two newer styles had taken over, the informal English robe or "nightgown" with the back tightly gathered into the waist, and the more formal French or "sack back" gown with flowing pleats from the shoulders. Other variations included the polonaise (with the skirt looped up over the petticoat as in an image below), and more simple "round gowns", which were increasingly popular as neoclassical influences developed after the 1780s (see Heideloff fashion prints below). Fabrics chosen were usually woven silk brocades or damasks, often in a stylised floral design until the 1770s, with simpler printed cotton callico and linen, or embroidered cotton muslin, increasingly fashionable thereafter.
Full item descriptions:
"wedding dress & stomacher & petticoat & necklet" [1951.281]
"polonaise dress" [1947.1606]
"caraco jacket" [2003.171]
"pet-en-l'air jacket" [1999.171]
"The Gallery of Fashion (19 plates)" [1964.131/19], Heideloff, N