“Setting the stage: design and display at the turn of the century” analyzes the foundations of department store window display in the early twentieth century, a time when trade publications and fixture companies dominated any and all discourse around the art of interior display and salespeople were an indivisible part of the selling process. The 1920s saw a marked change in how store companies and fixture suppliers approaching emerging theories of merchandise display, which combined window trimming’s roots in the theater with museum display techniques to create new, eye-catching forms of display that would forever influence the way stores advertised their products and how people shopped for them. This chapter further examines how department stores transformed from wholesalers to mass retailers, defining the American cultural landscape in the process.