I had to do a research paper in high school about somebody during the Revolutionary War (jeez, that was over 10 years ago now... what happened to the time?). After researching various characters, I came across Peter Francisco. Ever since then, I feel like his legend has been extremely underutilized in movies / games / etc. He could have shown up during Assassins' Creed 3, and there could easily be a questline added to Fallout 4 with all the Revolutionary War influences.

He was a tall guy with a giant broadsword and supposedly picked up a cannon and carried it to safety... Maybe another robot / synth like the USS Constitution questline? At the end you get a special broadsword and a special cannon.

Maybe have the quest start somewhere outside Boston - he has a memorial thing somewhere in Mass.

Here's a little more info about him:
https://www.youtube.com/watch?v=3jRyxgip5ew

Hey Boris, I owe you an apology. I thought some guy was using your name etc....Sorry bro and keep up the good work.