More research has been conducted regarding women's costume history than that of men's historic costume. One area in which little research has been conducted concerns men's boxer underwear. The need for additional research dealing with basic style changes of men's boxer undershorts was compelling to this researcher, as well as adding to the literature concerning men's historic costume. The purpose of this study was to research the availability of men's boxer undershorts post World War II (1946-1988). Specifically, based on pictorial underwear fashions illustrated in the Sears Annual Merchandise Catalog, this study documented and analyzed the availability of boxer undershorts as to fiber content, fabric structure, color, style features, and special design motifs during the time period studied. The objective of the study was to increase the knowledge of men's historic costume through an investigation into the styles of men's boxer undershorts. The historical continuity of fashion, as well as other theories concerning fashion change served as the theoretical framework for this study. The historical continuity process of fashion proposes that each new fashion is an evolutionary outgrowth and elaboration of the previous fashion (Blumer, 1969). Examples include past research by Young (1937), Kroeber (1919), and Robinson (1976), which indicated that changes in fashions took place in well-defined cycles. It is believed by some researchers that broad fashion trends follow an evolutionary process. However, specific fashion details and styles may be a result of social events, technological advances, and other cultural activities. Studies by researcher's such as Baker (1962), Nugent (1962), and Behling (1985-1986) found relationships between women's clothing and changes in society. To document and analyze men's boxer undershorts, Sears Annual Merchandise Catalog was selected. Spring/Summer issues in two-year issues were chosen between the years of 1946 and 1988, which yielded a sample of 237 boxer undershorts. With seriation of the boxer undershorts, a frequency distribution was completed. Five research hypotheses were tested to accomplish the objective of the study. Results indicated that there were differences between the frequency of occurrence among a) fiber content, b) color, and c) style features. However, there was not a significant difference of occurrence among fabric structure of men's boxer undershorts. In addition, due to lack of information concerning fabric design motifs, an analysis was not able to be performed concerning this hypothesis. These findings support the belief that there are broad changes in boxer undershorts which follow an evolutionary process, however, specific changes in details are a result of society's influence. This is evident in the changes concerning fiber content, color, and style features which were influenced by technological advances. The fact that fabric structure of boxer undershorts was not influenced by society suggests that this is a broad trend which follows an evolutionary process. Comparing these results with data collected from advertisments in a fashion magazine such as Esquire is suggested for further study. The data also suggest that further study comparing the trends in style features of boxer undershorts documented in this study with those of men's trousers of the same time period would provide another topic for research. / Graduation date: 1991