Perhaps this is more of a question about how terms develop in the first place, but I recently realized that even though potato chips were invented in America, they have a different name in England (crisps). How did that come about? I would expect that such a thing would “default” to the name the originating country gives it, since both speak English (of a sort). I know a different name didn’t come about just to be contrary, so how/why did Great Britain “ignore” the American name, and why doesn’t this happen a lot more often?
I can’t answer the “why”, but as for your second question, it actually happens quite often.
What we call “French fries” are sometimes known as “chips”… a car hood is known as a “bonnet”, a trunk is a “hood”, etc.
Here’s a nice little dictionary of English to American:
http://english2american.com/
From what I can find online, from various sites:
The American ‘chips’ date from the mid-nineteenth century. ‘Crisps’ was first used by the Irish company Tayto, in the 1940s. By that date, ‘chips’ was firmly established this side of the Atlantic as the big chunks of potato, so they had to choose a different name for the newly-imported snack.
Every linguistic difference (of which there are many, and many threads to search for discussing them) will have its own explanation.
I’m sorry, I don’t understand that last sentence. So what if “chips” was already used as a word for them in America? Was it a case of, like aspirin and cellophane, a trademarked word becoming generic?
No, ‘chips’ was already in use in Britain, instead of ‘fries’.
I was going to start a new thread but I could just ask here:
Does anyone know if there are any grammatic differences used between the US version of Windows and the UK version? Is there even a UK version?
There is a UK spellcheck on Windows.
Remember, people left the British Isles for America in waves starting from the 17C up to 19C. They took regional dialects with them, so Anglican people settling Virginia brought West Country accents/vocab, Puritan people settling New England brought East Anglian accents/vocab, Quaker people settling in Pennsylvania brought more northern/midland accents/vocab. Irish turned up in the mid 19C in NY etc.
Then you have Italians, Germans, etc turning up. Then in the late 19C/early 20C lots of new inventions came along, requiring new names for things (like parts of cars). But before instant telecoms, people adopted different words for them on different sides of the Atlantic. Now, with the Internet, jet travel, TV, etc, the differences are probably going to narrow.
Examples: young Americans are starting to use the delightful British phrase “wanker” or “wank”. and the old English usage “gotten”, which died out in Britain but continued in America, is now heard more in Britain.
So the differences might un-develop.
I would say that “chips” already had a well-established meaning in the U.K. - big chunks of potato, deep-fried, and served with deep-fried fish. Once you have a phrase like “fish and chips” so well-established, it would be confusing to have the word “chips” mean something else, closely related. If everytime you saw the word “chips” you had to ask the server if it meant “big chunks, deep-fried and hot chips” or the “wafer-thin, cold chips” it would be confusing. So since chips already had a well-established meaning, they used a different term for the new product.
This particular example only pushes the question back one level… how did two different terms, ‘chips’ and ‘fries/french fries’ come to be used for basically the same food item in britain/america respectively? 
Dex has largely answered that one.
Staff Report: What’s the origin of French fries?
The crucial point to note is that the Americans and the British independently imported the concept from France. It is therefore unsurprising that they then invented different names for it.
“The Brittish and the Americans are two peoples separated by a common language.”
Try this: Americans speak a variety of dialects, including one spread across much of the country, from Western Massachusetts to Alliance, Nebraska, called Standard American. Brits speak a variety of dialects as well, including one based loosely on upper-class and upper-middle-class colloquial usage of a half-century ago which has become “standard British English.”
Each dialect, including the two “standards,” evolved from colloquial local usage 300 years ago. There’s a common but not quite accurate canard that if you want to hear Shakespearean language used today as he would have heard it, you go to the Tidewater of Virginia and the Outer Banks of North Carolina, and listen to natives of those areas.
As new products and processes became popular, various dialects evolved different terms for them, and prior to serious satellite broadcasting, it was rare for an American to hear a Brit talking naturally, and vice versa. (You got elements of each, particularly the vice versa from the movies, but that was entertainment, without the immediacy of TV.) And note that South Africa, Australia, New Zealand, Jamaica, the other West Indies, and Canada all evolved their own dialects, which we’ll deal with lighter. 
Take, for example, purchasing a bottle of carbonated caffeinated non-alcoholic beverage from your friendly neighborhood convenience store, opening it, and taking a good thirst-quenching swallow. What is it that you’re drinking? A coke (as opposed to the capitalized short form for a Coca-Cola; I’ve heard “a coke” used for a Pepsi, which probably offends corporate moguls of both companies)? A soda? A pop? A soft drink? It depends on where you were raised and where you live how you answered that, even within the U.S.
The thing that mystifies me is why British publishers would give a completely different title to an American novel when they release it in England (or vice versa) (I think this happened with some of Hemingway’s works, for example). Now that just seems contrary.
That happened with Harry Potter and the Philosopher’s Stone, presumably on the grounds that the average American child would not know what a philosopher or the philosopher’s stone was, but would know what a sorcerer was (and wouldn’t care that “sorcerer’s stone” is a phrase invented by the publishers).
The answer is probably in the invention of the potato chip. They were created by a chef in Saratoga Springs, NY, after a customer who complained that his chips (English usage) were too thick and sent them back to be cut thinner. George Crum got pissed off and cut them as thin as he could just to spite the guy*.
These thin-cut chips (English usage) became known as “Saratoga chips” – chips cut and cooked in the Saratoga style. They were only sold in Saratoga until the Depression, when they began to be marketed nationwide (by Herman Lay). “Saratoga” was replaced by “potato” (it may have been a trademark issue, or Lay figured no one would know what “Saratoga” meant). Thus the US generic term was “potato chip.”
They probably were unknown in GB until after WWII. Since, by that time, “chips” had a specific meaning in GB, they were marketed as “crisps.”
*BTW, Snopes confirms this is NOT an urban legend.
Until the 1940s most British people had probably never encountered a genuine American, and *vice versa[/]. So the two nations didn’t really know much about each others speech patterns. Some American usages are probably survivors from older English forms which clung on in the New World. “They would never have gotten there” instead of “They would never have got there”. “He dove into the water” instead of “He dived into the water”. Others are probably German or Dutch. “I will write him” instead of “I will write to him”. “One hundred thirty” instead of “One hundred and thirty”. “How goes it?” is a straightforward translation of “Wie gehts?”
Noah Webster’s dictionary deliberately changed the spelling of some words just to make them more phonemic, or least not British.
Although there is a UK spell-check on windows we are stuck with “favorites” and “color” on IE and Widows.
I have noticed that American spelling creeping in , especially amongst the younger generation. On a UK board that I visit dealing with British TV I often see program instead of programme, license for licence and center for centre .
The name “crisps” were known in the UK before WW2. One of the earliest companies that made them (Smiths) have been around since at least the 1930’s. To complicate matters there are “game chips” which are very thin slices of potato , fried and freshly served with meat ( especially game!)