Often used was not the point. The Brits having different words (and weird spelling) for the same thing means that English is not English Britishisms 101: An American’s Guide to Decoding British English - a couple I don't agree with but most, yes.
Loo = toilet
Rubbish = trash
Boot (of a car) = trunk
Cash point = ATM
Rubber = eraser (not condom, a very important distinction)
Wanker, twat, tosser, chopper, a right plonker = idiot
Chuffed = pleased
Gutted = not pleased
Pissed = drunk (not angry)
Jiffy bag = padded envelope
Motorway = freeway
Lift = elevator
Fortnight = two weeks (this isn’t an old-timey word, it’s actually used today)
Chemist = pharmacist (not someone who works in a science lab)
Off license (also “offy”) = liquor shop
Booking = reservation
Arcade = mini mall (not a place of Skee-Ball, Pac-Man, and fun)
Trolleyed = drunk
Knackered = tired
Peckish = hungry
Jammy = lucky
Nutter = crazy person
Public school = private school
But wait, there's another list which also contains some I don't agree with The Differences Between American and British English Vocabulary
antenna aerial mad angry anyplace anywhere fall autumn bill bank note attorney barrister, solicitor cookie biscuit hood bonnet trunk boot suspenders braces janitor caretaker drug store chemist's french fries chips the movies the cinema rubber condom patrolman constable stove cooker wheat corn, wheat crib cot thread cotton wreck crash intersection crossroads drapes curtains checkers draughts thumbtack drawing pin divided highway dual carriageway pacifier dummy trashcan dustbin, rubbish-bin garbage can dustbin, rubbish-bin garbage collector dustman generator dynamo motor engine engineer engine driver movie film apartment flat overpass flyover yard garden gear-shift gear-lever alumnus graduate boiler grill first floor ground floor rubbers gumshoes, wellington boots sneakers gym shoes, tennis-shoes purse handbag billboard hoarding vacation holiday vacuum cleaner hoover sick ill intermission interval sweater jersey, jumper, pullover, sweater pitcher jug elevator lift truck lorry baggage luggage raincoat mackintosh, raincoat crazy mad highway main road corn maize math maths stingy mean freeway motorway diaper nappy vicious, mean nasty noplace nowhere private hospital nursing home optometrist optician liquor store off-license kerosene paraffin sidewalk pavement peek peep gasoline petrol post mailbox postbox mailman, mail carrier postman potato chips potato crisps baby carriage pram bar pub restroom public toilet blow-out puncture stroller push-chair line queue railroad railway railway car railway carriage spool of thread reel of cotton round trip return (ticket) call collect reverse charges raise rise (in salary) pavement road surface traffic circle roundabout eraser rubber garbage, trash rubbish sedan saloon (car) Scotch tape sellotape store shop muffler silencer one-way single (ticket) someplace somewhere wrench spanner faculty staff (of a university) oil pan sump dessert sweet candy sweets faucet tap spigot tap (outdoors) cab taxi dish-towel tea-towel semester term pantyhose tights schedule timetable can tin turnpike toll motorway flashlight torch hobo tramp pants trousers cuffs turn-ups subway underground railway shorts underpants shoulder (of road) verge (of road) vest waistcoat closet wardrobe wash up wash your hands windshield windscreen fender wing zipper zip
Actually it's Americans that have different words by bastardising English and turning it into a foreign language you call American English .
If your ancestors had taken a dictionary with them it wouldn't be a problem.