Vanguard tracks the index. The index are US large caps. In this case OP is right and vanguard is wrong. You should do a little research before you display such ignorance.
Like, find a company in the S&P 500[0] that is not an American company? A company named, oh I dunno, Linde plc, which trades as $LIN and was founded in Germany[1] and currently has its headquarters in the UK?
So on the technical merits, what I said was correct, the S&P 500 does indeed have non-US stocks. Further, on the general thrust of my point, that the S&P 500 has exposure to international markets, that also holds true, something like 71% US and 29% international based on some cursory research [2].
But please, continue to lecture me on my ignorance. :)