I usually hit the markets and junk shops- hell just about anywhere I think I can find some interesting bits of history.
I have been doing this for a good few years now and you never know what you are going to find out there....(I mainly focus on WWI & WWII- if I can find American Civil War I'd pick it up but its rather expensive and rare around here).
There is a few Modern US Army Items- in plastic bag, a 40'S to 50's US Areonautic first aid kit, a 1957 USN Flight survival flotation vest- with 2 smoker flares (intact), shark chaser, marker dye, whistle - seems to just be missing the flashlights. Also an assortment of WWII to 90's patches so Sterling Silver WWII pins (Rifle), A Pre to WWI OD tin mess cup, dog tag and a Red Cross ditty bag and such.
I mostly hunt for helmets but this was a odd helmet-free day.