This article talks about the last world cup final:

http://www.espnfc.com/fifa-world-cup/story/1950567/world-cup...

The US had 43.8 million people watching the final (in English and Spanish). Germany (who was in the final) had 34.65 million people watching. Even if Argentina had ever single person in their country watching, they'd only have 42.6 million people watching (wiki estimate). Granted Brazil almost definitely has higher viewership, but the US is definitely one of the largest.