Normally when this is asked, people think about reviving, curing, resurrecting. This question is about who you save if you were transported to a time a little before their death, like maybe a day before or even a week before. Anything about terminal illnesses or diseases contracted don’t really count here because, when those things happen, they happen and there’s really nothing you could do to have prevented it.
I think I would’ve wanted to prevent JFK’s assassination. I’d tell him “dude, do not get in that limo and drive down Elm Street” and I’d show him a newspaper clip of the day of his assassination. I’d probably be looked at a little crazily and suspected of maybe being involved in something that pertains to that day. But, it’s an effort I would’ve gone through to do that.


Andrew Johnson pardoning nearly every traitor so they could rot our country from the inside out like a cancer definitely didn’t help.
Sounds pretty damn similar to what the current corrupt administration does. So, before anyone dares say “No president in history has done this!” all they need to look up is Andrew Johnson.