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.
Received Pronunciation
Like all accents, RP has changed with time. For example, sound recordings and films from the first half of the 20th century demonstrate that it was usual for speakers of RP to pronounce the sound, as in "land", with a vowel close to , so that "land" would sound similar to a present-day pronunciation of "lend". RP is sometimes known as the Queen's English, but recordings show that even Queen Elizabeth II has changed her pronunciation over the past 50 years, no longer using an -like vowel in words like "land". 
Some changes in RP during the 20th century include:The change in RP may be observed in the home of "BBC English". The BBC accent of the 1950s is distinctly different from today's: a news report from the 1950s is recognisable as such, and a mock-1950s BBC voice is used for comic effect in programmes wishing to satirise 1950s social attitudes such as the Harry Enfield Show and its "Mr. Cholmondley-Warner" sketches.