North American English
There are a considerable number of different accents within the regions of both the United States and Canada, originally deriving from the accents prevalent in different English, Scottish and Irish regions of the British Isles and corresponding to settlement patterns of these peoples in the colonies. These were developed and built upon as new waves of immigration, and migration across the North American continent, brought new accents and dialects to new areas, and as these ways of speaking merged and assimilated with the population. It is claimed that despite the centuries of linguistic changes there is still a resemblance between the English East Anglia accents which would have been used by early English settlers in New England (including the Pilgrims), and modern Northeastern United States accents. Similarly, the accents of Newfoundland have some similarities to the accents of Scotland and Ireland.
Dialect levelling in Britain
Historical examples show that dialect levelling generally takes place anywhere and anytime in situations of extensive mobility and cultural and linguistic mixing. One historical example of dialect levelling is the change in the London dialect that took place in the fifteenth century when Northern county immigrants moved to London. Their dialect diffused into southern forms and some elements were incorporated into standard English (Milroy, 2002). Dialect levelling has become a widespread phenomenon in Britain. Southern features seem to be spreading throughout the whole country and typical vowel sounds seem to be centred on big cities like Glasgow, Manchester, or Newcastle (Kerswill, 2001).