Being as good as WW1 is a positive because the USA's emission peak was quite a lot higher still in the 1970s (per capita), I don't think this was criticism necessarily.

What surprised me, what I didn't know, is that the USA has been one of the highest for so long actually, starting to be worse than what most of the EU is today (~10t CO2e/capita/year) already in ~1903 and remaining that way even during the great depression. Being back to 1915 levels is not that bad with that kind of history (of course, until the ~1990s at the earliest, nobody knew this was an issue so no blame/fault for that era).