The brown hair horse is a bastard son of the farm owner and everybody treat him like trash, his mother is dead so he's living with his father. The owner of the farm also have another son, the little horse that'll inherit everything. (that's one of my theories)
Now... there is another one, a bit more dark: The brown hair horse isn't a bastard son, he's in really the son of the first marriage or adventure, but his mother was a native horse (I know there wasn't horses before in America until the arrival of the Spanish, but that not necessarily have to be an important fact here) or a slave horse, which could be dishonorable for upper class citizens at that time (nobody want a slave's son inherite a farm). Also, there's the new wife of the farm owner (a good citizen as you can see by the color of her hair) she was able to give him a thoroughbred son, who will now inherit without risking the family's renown, but she still feels threatened by the presence of the firstborn, who could claim his right to inherit.
On the other hand, there is the owner's brother, who seems to want to pressure the firstborn to kill his little brother and thus go to jail or be executed or disinherited. With no children to inherit, the property would pass to his closest family member, in this case, the owner's brother. There would still be the new wife, but in those days it was easy to kick a widow's ass or marry her to claim all of her late husband's property.
The brown hair horse is a bastard son of the farm owner and everybody treat him like trash, his moth
