Aluminium/aluminum is less British/American than you might think. Humphry Davy initially called it alumium, then aluminum, then it was decided by others to call it aluminium, which became the dominant spelling (which it still is, internationally).

Then, just to confuse matters, Charles Martin Hall promotes it as aluminum on his marketing posters, but himself calls it aluminium on his technical documents, so some people think that the predominance of aluminum in North America may just be down to a typo.

edit - Looking at the New York Times, I notice that while they write 'NASA' and 'NATO', they also tend to write 'Unicef' and 'Norad'. I wonder if they have a four letters or less capitalisation rule for acronyms.