The cut of men's suits and jackets varied throughout the 1920s and 1930s. The Sacque suits is traditional and what the average man wore. The saque is an unstructured fit, classic Brooks Brothers. The Oxford suit has a trim jacket with a nipped in waist and very full pants. The "Oxford bag" become popular in 1925 when Oxford University banned the wearing of knickers and plus fours in the classroom. Students loved sporty knickers; extra wide legged pants were made that could be worn over them.
Mid 1920s 'Jazz Suits' were trendy because after WWI, people started to live a different lifestyle that led away from the formal three piece suit with shoulder pads. Life became edgier, more party-like and men dressed in simpler clothing, with hats, and fashionable chastises to go out dancing and partying.