The shift is the basic undergarment for all women. It is usually a large rectangular shaped piece of fabric which is folded in half at the shoulder. More rectangles are added for the arms and gussets for the underarms.  The elbows were always covered as the eighteenth century person considered elbows very ugly. Linen tape was used to form a casing for drawstrings at the neckline. Sleeves were gathered at the elbow with a cuff, as the century drew to a close the gathered sleeve and cuff was eliminated as woman's fashions required tighter sleeves. Shifts were the closest garment to the skin and were used as nightgowns as well as an undergarment.  They were almost always made of white linen and a woman usually owned a few. Very few extant examples lasted through the centuries, it is thought once a shift became totally unusable the garment was probably given to a servant or a slave or cut up and the fabric used as rags, stuffing or for sanitary usage.

Shift vs. Chemise - Chemise is a French term. Unless you are portraying someone of French extraction, the garment was called a shift.

 

Want to make your own shift?  Mara Riley has excellent and very easy
instructions
to this very essential under garment.

Another excellent online source is found at The Northwest Territory
Alliance Patternmaster's
Shift Pattern.