Linguists can’t precisely pinpoint when “button-down” was redefined from cutting-edge collegiate to uniformly conformist, but the marketing expertise of the Gantmacher brothers of Brooklyn probably had something to do with it.

Beginning in the late 1940s, Martin and Elliot Gantmacher popularized the button-down shirt as a de rigueur garment for Ivy League and Madison Avenue men. They were so taken with their success, in fact, that not long after their company was rebranded Gant in 1949, the brothers adopted the label as their surname.

Elliot Gant, the last of the founders, died on March 12 in Boston. He was 89.

The Gants did not invent the button-down; the venerable Brooks Brothers haberdashery had borrowed the style from British polo players decades earlier, and it had been romanticized here and there in popular culture.

In John O’Hara’s 1935 novel “Appointment in Samarra,” Caroline English dreamily recalls Ross Campbell as “one of those Harvard men, tall and slim and swell, who seem to have put on a clean shirt just a minute ago — soft white shirt with button-down collar — and not to have had a new suit in at least two years. He was not rich; he ‘had money.’ ”