Claire McCardell

McCardell has an entry in the 1950s section too, but if I had to pick the decade where she matters most, it's this one. The 1940s is where her whole approach - function first, comfort as a design value, clothes built for a woman with no maid and a busy day - stops being an eccentric New York alternative to Paris and becomes, for a few years, the most sensible way to dress in America.

The war helped her in a slightly uncomfortable way. When Paris fell in 1940, American stores lost their usual source of ideas, and the L-85 restrictions of 1942 limited how much fabric a garment could use. For a lot of designers that was a cage. For McCardell it was practically a description of what she already did. Her 1942 "Popover" dress - a wrap-front denim dress with a matching oven mitt attached, commissioned by Harper's Bazaar as something to do housework in and sold for $6.95 - is the perfect example: cheap, easy, flattering, and cut from humble fabric. It sold tens of thousands of copies in its first year. In 1944 she worked with Capezio to put ballet slippers on the street, partly because leather for conventional shoes was being rationed.

What I love about her in this decade is the refusal to treat practicality as a compromise. Denim, cotton gingham, wool jersey, even the sort of plain cotton that sits close to feedsack prints - she used them as if they were luxury materials, with visible topstitching, brass hooks, spaghetti ties, and wrap closures that let one dress fit many bodies. She's central to the rise of American fashion during the war, and she's a big part of why, when Paris came back in 1947, American women had a genuine homegrown alternative to go back to if they didn't fancy twenty yards of skirt.