I am still trying to wrap my head around the fact that Spain's contribution to our fledgling nation was not ever mentioned in 12 years of public school, nor in the several years of college that I attended.
Anybody think that the war on fascism might have had something to do with such an omission?
Not really. Franco wasn't ever really our enemy. Couple of other factors that likely are more important:
Americans inherited a dislike from the English for Spain dating back to the Wars of Religion - they are pretty typically the villains in film and fiction, for example. Look at old - or even not so old - pirate movies, for example...
Most of American history early on was written by historians living in the Northeast, and tended to reflect that viewpoint. This is referred to as the New England Bias. Not a whole lot of Spanish influence in New England, so its importance elsewhere tended to be overlooked.
Plus, the US has had a bit of a crush on France - and they on us - for most of our history. Sometimes that crush manifests itself in anger and mockery, but it is there all the same - neither country is really indifferent to the other. That tends to lead us to focus on France to the exclusion of other nations, I suspect.