Sam traveled outside his lifetime? When? To where?

During the Final Season Of Stunts. Civil War, if I remember correctly - turns out his great-great-great grandfather has exactly the same DNA, so that... changed things! Somehow. Oh, don't ask me to explain it, at least there weren't any miners or bartenders involved.

Sam traveled outside his lifetime? When? To where?

There was some episode during the flailing gasps of the last season when he traveled back to an ancestor of his during the Civil War or something. I'm not sure I ever saw the ep.

I thought the special travel was when he went back to be himself as a teenager, and tried to prevent everything bad that was going to happen to his family in the future, but then realized that his father was still going to have a heart attack and his sister would still marry an abusive man.

Oh, that was a great episode. And the one right after that, when he went to Vietnam to save his brother.

Oh, and that episode had Bakula sing "Imagine" in a sort of country style, all twangy and forboding.

Hmm. I've found a very bizarre AU Stargate series. Started out weird enough -- alternate universes, a not-organic-but-not-detectably-nonhuman body, a Daniel who's not only not quite Daniel but doesn't even belong in that universe, and a Jack who's the only one who knows but who doesn't tell him, allowing Daniel to think that his memories of Skaara and Sha're as hosts are completely wrong. But now it's entered a 74-part unfinished series with Chronos and the woman who was Amonet's host in this universe and and... it's so weird. Kind of like Mountie Slayer in the intricacy of the secrets and the part where you go, hey, but you did this thing back here, aren't you ever going to bring it up again? Actually, the Mountie Slayer series always does bring stuff up again. This series is actually more like the 3-million-year-old-babe episode, in that it's got a really big (seeming) plot point in the very beginning which it uses to set up a completely different story. For some reason I'm still reading, but it is very strange. I keep hoping Daniel's going to discover the Truth About His Past, but at this point it would probably seem insignificant, since for totally unrelated reasons he's got the fate of billions in his hands and almost every Goa'uld in the universe out to kill him.

And I felt like sharing that with you. It's freaky but fun, but also a little frustrating. I mean, if she never brings up his Amazing Transdimensional Secret then it's a thread that just falls off into nowhere, so I keep reading, but I'm starting to get a little impatient.

you end up wondering why the hell Sam Beckett wasn't sent back to kill Hitler

If they played that the way Stephen Fry did in Making History, that could have been a riot. (Very short summary: preventing Mrs. Hitler from conceiving made the whole thing worse, as someone subtle, intelligent and Hollywood-worthy took the top spot.)

I saw one Twilight Zone where a woman was sent to kill Hitler as a baby, only it turned out that she killed the wrong baby. She did kill the child of Mr and Mrs Hitler, but then the nanny in charge bought a replacement baby and the parents never knew - which might suggest something about why he ended up evil.

Sounds vaguely like the plot of Good Omens.

There's a bit of similarity - and the idea that there's only so much a human can do to alter what Fate wants. That, or both writers had strong opinions in the nature vs. nurture debate.

One of the premises of Fritz Leiber's Changewar series (which was exactly about two opposing groups that went back in history and fucked with the timeline to eradicate the other) was that forces of history were difficult to divert. Everybody should read The Big Time and somebody should make it into a play too.

To Say Nothing of the Dog comes to the same conclusion.