Thank you everyone for your sympathy and suggestions. This is as far as I've gotten to know Coop I was building so it's not too late to change things up a little. I think I can buy Lowe's grid panels like you use on a dog kennel at Tractor Supply that will fit the sections on my run. Should I only use the chicken wire to go around the perimeter around under the ground to help prevent something from digging?
Sorry you lost the birds Daniel
My bet is the coon went through the nest box door. Were the chickens eaten or just the heads ripped off? The latter is, I gather, a signature coon move.
Use chicken wire ONLY for fencing that you HOPE will keep the chickens in or out of something. It has NO use against predators other than to slow them down a minute. Coons can reach through it and rip the head off a chicken laying against it.
Run protection: All sides should be covered with welded wire or chain link if you are using dog kennel panels. If you are worried about big digging predators, you can put down a 2x4 wire fence skirt down into the ground a few inches then skirted out at least 18". You need 1/2" hardware cloth up about 2 feet along the outside to keep coons from reaching in. Make sure the strike side of the door can't be pulled away from the frame down low to create a small gap. If it can, put a second latch a foot or two up from the ground. My preference is barrel bolts with a hole for a lock/carabiner.
Coop protection. EVERY opening, no matter how small must be covered with 1/2" hardware cloth. Even a big "fat" racoon can squeeze through an opening you would think impossible. Ever seen a small weasel? (you have them even if you haven't seen them) They can get through a 1" hole and will play vampire on the back of your chickens' necks on the roost at night. Larger openings (something a larger predator can get in) can also be covered with heavier gauge wire fencing if you have big predators with big teeth. If they can manage to hook into the 1/2" hardware cloth, they can chew through it.
A word about "staples". T50 "Arrow" staples will pop out with almost no pressure on the wire, use them only to position the hardware cloth. Fencing should be attached with poultry (fence) "staples". 1/2" hardware cloth (don't use 1/4, smaller wire size) with that or screws and fender washers or battens screwed over the wire.
All doors/access hatches, whatever, must have coon proof latches. That means something you can put a lock or carabiner through. And if you use gate latches, make sure you put a trip wire fed through the door to the inside so you don't have to spend hours with the chickens until someone rescues you when the door blows shut when you aren't looking, or your goat closes it on you, or .... You may laugh but read through some of the forums and you will see that it happens more often than you may think.