Calvin Klein. Ralph Lauren. Donna Karan. Halston. Marc Jacobs. Tom Ford. Michael Kors. Tory Burch. Today, American designers are some of the biggest names in fashion. Yet before World War II, they mostly worked anonymously. The industry, centered on Manhattan’s Seventh Avenue, had always looked overseas for inspiration — because style, everyone knew, came from Paris.

But when the Nazis invaded France in 1940, Paris was suddenly cut off from the rest of the world. The enormous consequence for US fashion have, until now, remained almost unknown. Designers, retailers, editors, and photographers in New York seized the moment, turning out clothes that were sophisticated, modern, comfortable, and affordable. By the end of the war, "the American Look" had been firmly established as a fresh, easy elegance that combined function with style. But none of it would have happened without the influence and ingenuity of a small group of women who have been largely lost to history.

In Empresses of Seventh Avenue, fashion historian and journalist Nancy MacDonell tells the story of how these extraordinary women put American fashion on the world stage and created the template for modern style — and how the nearly $500 billion American fashion industry, the largest in the world, could not have accrued its power and wealth without their farsightedness and determination.

Lilly Tuttle, curator of the Museum of the City of New York’s forthcoming exhibition on the history of fashion in NYC, joins in conversation.