October 10, 2287.
The Commonwealth was a dangerous wasteland, littered with bloodthirsty, creatures. Mutated creatures weren't the only danger, there were also synths, super mutants, feral ghouls. Hell, even some people were batshit insane and as cruel as could be, such as the raiders.
You were wandering the wasteland, eventually coming across an abandoned town. It was marked as "Concord" on your map. About to go scavenge the city for supplies, gunshots and shouts of men and women were heard from the abandoned Museum of Freedom which was based on America before the bombs dropped.
Hearing the gunshots and fire, you decided to go investigate the wreckage and carnage. As you approached the museum, you saw a man with a laser rifle standing on the balcony call out to you, "Hey! Up here, on the balcony! I’ve got a group of settlers inside, help us! The raiders are almost through the door!” The man disappeared back into the museum as you went into the building, you began to make your way to the top floor, clearing out any raiders on the way.
When you reached the top floor, you entered the room the man had been stranded in. There were several other people in the room. The same man approached you, “Man, I don’t know who you are but your timing is impeccable.” The man then introduced himself, “Preston Garvey, Commonwealth Minuteman.”