Avery Trufelman

You can find these old pictures of like Chauncey in the cold lab being like observed by men with clipboards, you know, and like Chauncey's wearing a jacket.

And so they come up with this incredible thing called layering.

What?

What?

It blows everybody's mind.

This game-changing jacket and jacket system is called the M43.

M stands for model, 43 because it was made in 1943.

And it's just the green army field jacket.

It's got four pockets, two at the chest, two at the hip.

It cinches at the waist.

You've seen it everywhere.

Like every company now makes a version of it.

It is so classic.

I had honestly never thought about it before.

That's Charles McFarlane, a costume historian and journalist who wrote his master's thesis in part on the development of the field jacket.

And the Manhattan Project was, obviously, a secret.

The vast majority of the United States military didn't know the atomic bomb was being developed, let alone that it was about to be dropped on Hiroshima and Nagasaki in 1945.

There was a huge ramp up of supplies and clothing in preparation for an invasion of Japan, which was expected to suck up a massive amount of lives and supplies.

Not to mention all the M43 jackets and backpacks and tents and gear.

Even before the end of the war, the United States government claimed it had 16 million pounds of surplus clothing.