July 1944
I hope the original credits/copyright appear in the comments soon, here and/or in response to the flickr photo you can get to if you click through.
Here's another unattributed photo that I haven't found a source for. Would love to know, as I'm sure not all of these are in the public domain or creative commons. So many good photos like that are out there in the wild.
One of my favorite things about Flickr is that I can explore the creative commons photos there, and both use them and give credit where it is due.
