That was a formal standing army, with a logistical train.
When I was in the Marines, doing a hump, we carried our pack, Shelter half, sleeping pad, wet/cold weather gear, two canteens, a flack, rifle, and brain bucket.
We did not carry additional water or food. That was brought up by the sag vehicles and field expedient chow hall.
I am referring to a post-SHTF situation. Are you going to be gardening with plate carriers, rifle slung, additional ammo? Or how about walking to the neighbors a mile or so down the road? Moving livestock to the next paddock, in the fields over uneven terrain?