Different varieties of French fries. From left: regular, waffle, and crinkle-cut (wavy) fries

French fries were first recorded with, and presumely invented by, warriors in the Andes Mountains in the 1620s. Fries, in their modern sense, were even eaten by Thomas Jefferson!

French fries are often said to have been invented in Belgium, which is why they're called "French" fries (sense French is spoken in the country), but this isn't true. The name originated through the method of frying, called "Frenching." The name "French fries" was in use prior to WWI, so the Belgium myth doesn't make sense in that regard either. Sorry to burst your bubble.