Two developments influenced women's clothed during this decade: the design, by Mary Phelps Jacobs, of the brassiere in 1914; and the increase in the number of women in the workplace - because of war - which necessitated less restrictive clothes. The three-piece lounge suit - narrow trousers, jacket buttoned high on the chest, with small lapels, bowler hat - became popular daywear, as opposed to casualwear, for men.