a) By 1817, trousers were shoe-length. Popular with the king, they became accepted as standard daywear by 1825, and were worn with a waistcoat and, by day, a frock coat, but with a tailcoat in the evening.
b) Jackets didn’t become fashionable for casual wear until the 1850s. The jacket was derived from the short jacket worn by boys and working men, and in the age of mass-production and ready-made suits, its simple style was easier to produce than the tailored coat.
c) It was George “Beau” Brummell, the champion of simple English style, who started a trend for wearing tight black trousers in the early 1800s.
d) The favorite patterns for trousers were strong plaids, stripes and checks. The loose straight cut came in about the 1860s, and front creases in the 1880s. By the turn of the century, they had become the common way to dress.