This part of the story is one of the reasons I'd give this book such an excellent review - I'd read the story of Emily and the children's lives on the prairie. As a white person of privilege who is working harder and harder to be a better ally every day, I believe any person who is perceived as "different" in the way they look, talk, or act has a more challenging time when they are in the minority. Therefore, I'm sure Gabriel's life was not without challenges. However, Gabriel was free, with people who loved him, and hopefully with people who respected him as an equal - or at least tried to in as much as their societal contexts were able to allow them to do so.
I just saw a story about a black cattle rancher (modern day) who was inspired by a photo he had seen of a historic group of black cattle ranchers. It was a quick passing glance at an article rather than a deep read but I thought of Gabriel when I read that.