Of course, in good food tradition, the French claim to be the inventors of our beloved fries. As with most "French" inventions, they forgot to note the name of the inventor and they are still searching for proof. Actually the word "French Fries" has nothing to do with the French.
Pictures and texts proof that fries were all around our country in the second half of the 19th century. The oldest written proof is dated 1862 and mentions a certain Fritz and the widow Descamps as owners of a fry stand on the Liège 'kermis(=fancy fair)'. In 1891 a picture of both stands was taken.
Jo Gerard, a famous Belgian historian, claims to have proof that fries were invented in the region of the Meuse in 1680. Based on an unpublished document, he writes that the poor inhabitants of this region ate mostly fish. When the river frooze, they cut their potatous in a fish-shape and fried them.
The Americans have their own story. I quote 'The Official French Fry Page': "French Fries, at least in the US, seem to have been first named "Potatoes, fried in the French Manner," which is how Thomas Jefferson described a dish he brought over to the colonies in the late 1700s. Presumably, he brought over the method, and not an actual plate or two, as they would have become rather soggy and possibly rancid on the 5- to 8-week Atlantic crossing. He served this to guests at Monticello and it became popular, serious dinner fare."
Nothing much on the history of chips in Great Britain except this quote from the Dundee City Fact Sheet: "... whilst, in the 1870s, that glory of British gastronomy - the chip - was first sold by Belgian immigrant Edward De Gernier in the city's Greenmarket.
Why are they called "French Fries"?
Explanation 1: the French invented fries, that's why we call them French Fries. Wrong, as we have seen above.
Explanation 2: during the first World War, American soldiers came to our country and discovered our fries. As the inhabitants spoke French (the biggest battles were fought in Ieper near the French border), the soldiers called them French Fries. Wrong again.
In fact, the explanation is quite simple: in English, 'to french' means (or at least meant) 'to cut into lengthwise pieces'. You probably know 'frenched beans'. So logically, French Fries is short for 'frenched and fried potatoes'. In fact, the English call them 'chips', a word which has a similar meaning (a chipped piece of wood).
Anyway: it's Belgian Fries, not French Fries, so it doesn't matter, not?