Wow! I can't wait to hear what your friend does next.
1. Interesting he won't go in the barn because that is where their home is. It really was risky business for you to spend last night in the barn.
My only question is if these are Native American spirits then why are they going after my animals?
Two tribes were at war. My theory is much livestock was probably stolen by the intruders and no doubt many horses were killed on both sides during battle.
The tribe who had first rights to the land may have lost the battle and are still seeking retribution against anyone stepping on the land they hold sacred and as belonging to them.
Hopefully your friend can make peace with them in some way - it will be historic since this has been going on for a few centuries.
Learning which tribes and what the battle was about would make a really interesting read.
The first owner built a home in 1859? You meant to say 1859 not 1959 and left ten months later? What a story what a story. This is worse than the folks I mentioned earlier who unwittingly built a home on sacred Indian ground and the house had a spirit living in it.
Tomorrow is Sunday, typically the White Man's Christian Day of worship. Will that make a difference, regarding how the Spirits might receive your friend's peace offering? He is Native American, so I hope not.
I think you were pretty successful in your detective work. That's way more than I expected you'd find
Gosh I am hoping this gets resolved in a positive way for you.