The earliest bathing dress for women in the United States may have been an old smock or shift, followed by a bathing gown based on the shift or chemise. Although women's bathing and swimming costume achieved an identity of its own during the 19th century, the evolution of this garb followed certain innovations in women's underclothing, namely, drawers in the first half of the 19th century, the "combination" of the late 1870s, and the brassiere and panties of the 1930s. The greatest number of minor style changes, however, were direct reflections of fashions in street dress. The rising hemline and, at times, the discarding of a skirt during periods when women wore long dresses for other activities can be attributed to changes caused by the functional requirements of bathing and swimming; the shortening of sleeves and trousers in the last quarter of the 19th century were also functional improvements. The benefits of the shorter trousers, however, were minimized when modesty required women to cover their exposed legs with stockings. Swimming suits have been considered a 20th century innovation; in fact one corporation is under the impression that a member of their staff was responsible for the first use of the term "swimming suit" early in the century. The findings presented in this paper show that some women were wearing "swimming suits" that were distinctly different from bathing dresses as early as the 1870s and that both co-existed for some 50 years. Bathing dresses disappeared in the 1920s with the widespread acceptance of its functional counterpart; "bathing suit" no longer referred to a special type of costume but became interchangeable with the term "swimming suit." The insistent trend toward more functional costume reached its ultimate conclusion with the refinements of the knitted swimming suit in the 1930s. Subsequent changes have not improved upon the functional design of this classic suit. In many instances these variations have been merely to satisfy the feminine desire for distinctive apparel and the industry's need for perishable fashions. Female competitive swimmers have continued to wear the simple knitted suit--now of nylon rather than wool. The changes since the 1930s have shown a trend toward diminution in the coverage of the swimming suit. One cannot be certain what this means for the future, but it is unlikely that either the swim suit industry or standards of modesty of the near future will permit a total elimination of swimming costume. We can be assured, however, that so long as women swim, they will not repeat history by swathing themselves with yards of fabric. U.S. GOVERNMENT PRINTING OFFICE: 1969