Despite appearing in the same game as Nate and having been born over a hundred years later, MacCready, shares many of the same circumstances as Nate, and in many ways, MacCready is the third act in the trinity of tragedy that begins with Nate and Kellogg.
The game fairly well hammers home the rise and fall of Kellogg during the exploration of his memories, and it highlights the similarities of how his chance at a fairly picturesque life was stolen from him. Only for him to ultimately go on to be the cold, needlessly violent killer who stripped the SS of their shot at a normal life.
The similarities between Nate and MacCready are even more apparent. Though the former mayor may not technically have been a Vault dweller, the cave "city" of Littlelamp Light was essentially the back porch of one and as apart from life in the wasteland as any dweller would have. His life as a mercenary was he was about as close to being a solider as one could expect on the east coast. And his personal slice of happiness was taken from him just as brutally when his wife was swarmed and killed by feral ghouls. A fate he was powerless to save her from but forced to watch unfold in front of him. Crucially, what separates MacCready is that his story can be the first to avoid complete tragedy. Because of Nate, not in spite of him, MacCready can actually save his son, and in doing so, manages to hold on to something neither Nate nor Kellogg could.
