|Cotton cords, Drills, Fustians, Jeans etc.,
This classified ad from the Chelmsford Chronicle of 17 April 1829 shows that you could buy a pair of jeans from the Regency equivalent of Primark at 88, Whitechapel High Street, just 'thirteen doors down from Brick Lane'.
Chances are, your new jeans wouldn’t have been made in a sweat shop in the far east, but would have arrived at the London Docks ( just down the road from Whitechapel) on a boat from Genoa, the word jeans being derived from ‘Genes’, the French word for the Italian seaport.*
Nor would your 1829 strides have been made of denim, which was made into pants (trousers) for Californian gold miners by Levi Strauss around 1854--ironically, Strauss was born on 26 February 1829, a couple of months before this ad appeared. The OED maintains that the 1829 cloth was originally known as 'jean fustian', which was abbreviated to jeans. It’s likely that back then your average Regency buck-- Corinthian Bob or whoever-- wouldn’t have been seen dead in a pair of jeans (or in Whitechapel High Street, for that matter) and would have associated them more with sailors from Wapping or Shadwell dock workers.
*The word 'denim' is also of French origin. It comes from the name of the sturdy fabric called serge, made in Nîmes, France, by the André family. Originally called Serge de Nîmes, the name was soon shortened to denim...