From 1900 until roughly the middle of the century, fashion remained largely the same. Men wore a fedora and suits. Women wore dresses, and occasionally some form of hat. More relaxed wear did change. However, these fashion senses largely remained the same even with variations. That began to change after WW2, with the adoption of a California fashion sense. From the 1950s through the 1960s, the traditional fashions began to fade. Suits became more formal-only wear, and everyday dress became more casual. The fedora fell totally out of fashion with all but an older generation.
The challenge is to keep the fashion of the first part of the 20th century fashionable.