Does "hardcore" come from baseball?

I’m wondering where the term “hardcore” originated, in the sense of a Hardcore gamer, hardcore pornography, etc.

According to http://www.m-w.com/dictionary/hardcore , the British use the term to mean the gravel or broken bricks used for making a road bed.

But I’m wondering: Here in the good ol’ U.S. of A., did the term perhaps originate from the construction of baseballs?

Little kids learning the basics of baseball will often use a ball that’s the same size as a real baseball, but made out of foam rubber (a “soft core”, as it were). Real baseballs, on the other hand, will be made of a layer of bleached leather covering yarn that’s been tightly wound around a cork core, so as to be rather hard.

So, does the American usage of “hardcore” to mean someone or something that’s “serious” or “earnest” come from baseballs?

Porno…?

with a lot of other hard things removed. Not a real help but mostly a cite saying that the term was around before it was applied to pornography.

Yeah, you know. “Hardcore pornography” as opposed to “Softcore pornography”. Basically, whether it gets an NC-17 rating or can instead squeak by with an R rating.

Also from Etymonline:

Which suggests that this came before the adoption of ‘hardcore’ into the porn lexicon.

It also appears, according to that site, that “hard-core” as slang for “tough” in general comes from 1951.

While this is certainly well after baseball became the National Pastime, it might not be that long after the introduction of soft-core “practice” baseballs for youngsters learning the basics of the sport.

I doubt it. Kids called them hardballs (and that term comes from baseball), softballs, spaldeen (rubber balls used for stickball) and whiffle balls (for the company that made the hollow plastic baseballs). I never heard of a hardball being called “hardcore” in a baseball context.

The MPAA doesn’t generally rate hardcore pornography. Especially as it’s rarely released in theaters these days.

I suspect that “hardcore” evolved from “hard-hearted”. “Heart” is/was frequently used to refer to the center of some things: heartwood is the wood at the center, or core, of a tree, for example. Figuratively speaking, a person’s heart is their center, or core, and “hardened” criminals are often hard-hearted. This could have been conflated with the phrase “rotten to the core”, and you end up with “hardcore”.

Just a WAG.

“Hard core” meaning “tough” or something akin is definitely only from the 1940’s, in American English, and seem to be derived from the military. More than that, I don’t have at this point.

Hardcore is the broken up hard brick or rock which at one time used as a base for roads.

If only the OP had said so!