I hadn’t really thought about it until just now..... but I suppose it would be between my 1943 Ithaca 1911A1 that was my dad’s WW2 sidearm, my S&W 5” Model 29 Classic, or my S&W 340M&P. I own a Springfield Loaded 1911A1, but it was Brazilian made. I have two other S&W revolvers - a 640 and a 642 - but I like the light weight of the 340 and the power of .357. But truth be told, ANY pistol my 2nd Amendment right allows me to carry would be suitable for me. I’d consider it no less American to carry my Austrian manufactured Glock 19 as anything else.
Rifles? All of mine are American made, either by me, or by American companies. The one that would be the most “commemorative” would be my 1943 Inland M1 Carbine, or possibly my Marlin .30-30. But heck, I also have a FN SCAR 17S too, and now even those are built in America, so.......
As for what I will actually carry today - holiday or not - it will probably be my 340M&P, either pocket carried or concealed OWB, as it is very light, and I will be attending an outdoor BBQ in my old neighborhood, sporting a Hawaiian shirt, cargo shorts, and flip-flops. I sweat like a hog and don’t want to sweat all over the gun, so it will most likely be pocket carried. I probably won’t bring a long gun along at all. I will be among friends, in a safe and quiet neighborhood, not that far from home, and I’ll be home before dark to help my dogs stay calm. The risks are low.
The fact is that for me - and this is just MY taste - I tend not to distinguish between guns/holsters gussied up to be carried for a celebratory reason, and anything I’d carry daily. I can appreciate the art that goes into making beautiful holsters and tarted up carry guns, but it just isn’t my style.