Where does Blazer come from?
The blazer comes from Cambridge, England. The first blazers were the bright red flannel jackets of the Lady Margaret Boat Club, the rowing club of St John's College, and their name later spread to club jackets of every kind.
Red jackets on the river
Twelve members of St John's College founded the Lady Margaret Boat Club in 1825, the first college boat club in Cambridge. Its members rowed in boating jackets of bright red flannel, a popular cloth of the 19th century. The club says the jackets were called blazers because of their distinctive bright red cloth, and the dress historian Jayne Shrimpton writes that they were apparently so vivid that onlookers described them as setting the water ablaze.
From one club to everyone
The word soon outgrew its first meaning. In 1889 a writer to London's Daily News complained that at Cambridge a blazer had meant the Lady Margaret's red jacket 'and nothing else', but now seemed to mean 'a coloured flannel jacket, whether for cricket, tennis, boating, or seaside wear'. By the 1890s blazers were worn with white flannel trousers and straw boaters, and in the early 1900s they joined school uniforms. From the 1930s the blazer began to shed its sporting links.
Why people say New England
The blazer, traditionally navy with metal buttons, is a staple of Ivy League style, which grew on the campuses of elite universities in the northeastern United States from the 1920s, became mainstream in the 1950s and led to preppy fashion. But that style borrowed the sporting clothes of the British and American upper classes. The navy version probably owes much to sailors' short double-breasted reefer jackets. The name itself began on the river Cam.
Sources: en.wikipedia.org › Blazer ↗ · ladymargaretboatclub.org ↗ · thegenealogist.co.uk ↗ · en.wikipedia.org › Ivy League (clothing) ↗