potofsoup:
Pretty sure it’s not canon, but it’s got quite a bit of fanon support.
I am fully on-board with the MCU Bucky being a Bucky Barnes/Arnie Roth combo character as far as backgrounds go.
Personally, I figured Buck for another primarily Irish-stock kid, albeit better off financially and less fresh from the boat than the Rogers family, but I wouldn’t be in fandom if I didn’t love different character interpretations, and Jewish Bucky is totally valid, especially if you take the Roth influence into account.
One of the most interesting aspects of the Captain America lore, to me, is how often Cap has been mythologized in his own universe. In the earliest comics, Bucky is the child companion to super-soldier Steve Rogers. Which is… kind of bizarre and creepy given the WWII context? It didn’t take long for other writers to realize this, so in later iterations — like the Waid or Brubaker runs, for example — Bucky being a kid is ret-conned, except it’s framed in a way that doesn’t invalidate the earliest Cap stories. Rather, they’re treated as sanitized versions of the “real” story, which is that Bucky was either a war photographer who befriended Steve and/or at least 16 when he was sent out to accompany Captain America as an orphan who was raised on-base to become a specialist in scouting and wet-works, who did things in the dark that an icon like Cap wasn’t allowed to do in the light. SUBTEXT.
The result is a pretty amusing comics meta, where we get to see the “real” Bucky complain about his 40’s GEE WHIZ, CAP portrayal on-screen — or rather, on-panel — and in the MCU, we get to see kids grabbing at Captain America comic books generated while Steve is on his publicity tours, which are in fact reproductions of the actual Captain America Comics #1.

Published in our world in 1941, and yeah, he’s totally punching Hitler. Did I say meta? IT’S ALL VERY META.
Another example of an in-universe non-ret-con is when WWII ended and Steve Rogers was floundering as a character (what to do with a Hitler-puncher when you have no Hitlers to punch?) but the Cold War was gearing up and McCarthyism was hot, so the best (??? lol) way to make him relevant was to go anti-Communism. Cap was even billed as CAPTAIN AMERICA, COMMIE-SMASHER!! before the title was altogether cancelled in the 50’s.
When Stan Lee revived him in the 60’s, he decided that the REAL Steve Rogers had been frozen since WWII, and the Anti-Commie 50’s Cap was an impostor.
But wait, this was about Bucky.
So, in none of the non-MCU iterations was Bucky actually Steve’s BFF from childhood. As of 1982, Steve DID have a childhood bestie, though. Arnold Roth. They met as weakling kids getting their respective asses handed to them in back alleys, then Arnie was like, “Screw this, I’m going to take up boxing.” So he did. And he got buff and used his new buffness to protect the still-sickly Steve Rogers from bullies on the daily. Thus continued their Best Friends Ever relationship, to the point where Steve considered the Roths a second family, and Arnold his biffle big bro. Also, Arnie developed a girl-chasing Romeo persona during their teens. I’m sure you can all see the parallels here.
However. The lady-killer rep was due to Arnold realizing he was gay and trying to over-compensate to hide his real desires, resulting in him eventually drifting apart from the more quiet Steve.
He later joined the Navy during WWII, and a whole bunch of other junk happened, (GAMBLING! ABDUCTION! DEATH! FRIENDSHIP!) but 616 Arnie Roth is canon Jewish and canon Steve’s larger, stronger, brunet age-mate protector. Make of it what you will.