|Marlene Dietrich sitting in 1st row 3rd from right, Hollywood Canteen 4th of July Picnic, 1944|
And many more Hollywood Canteen and USO images here and here.
EDIT: For those who clicked "dislike," please let me know why. My guess is that you disliked the low image quality, which also displeases me, but I at least appreciate that someone has compiled these shots and made them readily accessible. Please be aware that you may post anonymous comments and that I only delete spam. I welcome your feedback and wish for more conversation here.