… was a pair of  Killdoll wedgies, my new Kate Spade bag and the polished cotton sun dress I got at Tesco’s for a tenner:  full skirt, tight bodice, retro print.  It was the hottest day of the hottest July on record in New York, and my daughter and her friend, two English teens unused to heat that hits you like a wall, had to be chivvied onto the Hoboken ferry and up Fifth Avenue.  But the museum, the park at its back, was dim and cool.  We stood around in the main hall, fanning ourselves with the museum directory and then we climbed the stairs to the Costume Institute, a grand name for what turned out to be a modest nest of rooms.

The exhibit was called American Woman, clothing from the turn of the last century to the present day.  The mannequins were faceless, their arms straight down.  Walking through the first gallery, my daughter and her friend were flip, self-referential.  They said, to a bosomy ball gown, I wouldn’t wear that, and to her tweedy companion, I saw those boots at Topshop.

The corsets and bustles of the gilded age gave way to the mild active-wear of the Gibson girls: woolly swimsuits and ankle-length tennis dresses — like workout gear for sporty daughters of the Taliban.  Hair was looser, worn in ripples down the back.  We moved onto the First World War.  Men went to battle; women went to work, in boiler suits and rough cotton nursing uniforms.  The rules were starting to bend; two years after Armistice, American women won the right to vote.  A new generation – we were in the fourth gallery now — chopped off their hair and hacked at their hems.  They wore short, silky dresses over thin camisoles.  They rolled down their stockings and fastened their shoes with a single button.  Their necks, their knees, their views were public.

The rest of the exhibit was more familiar: the stars of the thirties and forties in their perky hats and slinky gowns, the pioneers – aviators, scientists, politicians – in flannel trousers and tailored jackets, the hippies and feminists in jeans and tees, women dressing for power in ties and pants suits and for sex  in hot pants and minis.  Images of Tyra Banks jostled with Susan B Anthony, Amelia Earhart met Carrie Bradshaw, and Eleanor Roosevelt vogued Lady Gaga and Hilary Clinton.

In less than a century, class, colour, wealth and gender barriers had come tumbling down.  The signifiers of status – the rich layers of fabric, the elaborate fastenings and complicated hair that required money, maids and leisure – had lost their grip and their power.  The shop girl and the debutant were indistinguishable.

For my girls, it was a light bulb overhead, a poke in the ribs reminding them that their choices, and their unquestioning right to those choices and aspirations – to be a judge, an entrepreneur, a slut – had a source and a history.

But, then, that’s how it is: start with the clothing and the rest follows.