After stumbling into concord, you had helped the minutemen with their raiding oppressors and systematically rescued them. As Sturges said, you took the T-45 power armor and made quick work of the gang.

So, after you help save the small group, you walk back into the Museum Of Freedom, Preston thanks you and gives you a handful of caps, not much, but a nice offering. However it’s the offer after this that is most intriguing, he speaks as he stands clad in his colonial duster, hat and with his laser musket held at a lowered position.

“We’ve been heading to a place called Sanctuary, why don’t you come with us? We could use some more of your good will.”

He asks, a simple offer on paper, a silent plea for help in their dwindling numbers and even further dwindling resources.

Because this really is all that’s left, one minuteman protecting a group of neutral settlers, Preston knows he can’t do it on his own, he knows how much rides on this moment alone.