It's not that Americans are against either of these per se; it's that they're indifferent. Ignoring people brainwashed by the right-wing propaganda against Wikipedia, sane Americans largely take Wikipedia for granted. I don't mean that bitterly; I mean that it's been there for 25 years, its quality is better than ever, finances are good, (edit: many people read it through some intermediary), and everyday people therefore don't consider how unstable its position really is, how much work there is to do, and how irreplaceable it is.
As for the IA, sample 1000 American adults. I'll bet you five or fewer could tell you what the hell an "Internet Archive" is.