Find a good deal on your flight from London to Watertown New York with Netflights. If you want to keep your options open, take a look at flights from another airport in London.
But when you fly is just as important as who you fly with. If you're flexible on dates, try searching by month to see when the cheapest flights are.
Or you could broaden your search by looking at flights to other airports in the USA to see if there are any cheaper options.
You can also compare the prices of hotels and hire cars for your stay in the USA. Simply use the tabs above, or add them to your booking once you’ve chosen your flight.