No, French fries aren't American (although we did pioneer their usage in pizza). They're not -- poutine notwithstanding -- Canadian, either. And they're certainly not French, at least according to almost the entirety of Belgium. Now, the Belgians want everyone else to recognize that fries are rightfully theirs, and to probably start eating them with mayo on top, too.
A campaign that began in the Flemish parts of Belgium has now extended to the French- and German-speaking populations, and is seeking to establish UNESCO world heritage status for fries, which were allegedly invented in Belgium and confused for French cuisine by American soldiers stationed there during World War I. With this status would come, essentially, ownership of the concept of fries forever.