English was inherited from British colonization. The first wave of English-speaking immigrants was settled in North America in the 17th century. In that century, there were also speakers in North America of the Dutch, French, German, myriad Native American, Spanish, Swedish, Scots, Welsh, Irish, Scottish gaelic and Finnish languages.
American English (アメリカ イングリッッシュ) is the form of English used by people in the United States. The U.S. government, business, mass media, and education system all operate using American English.
American English does not include Canadian English; although Canadian pronunciation and vocabulary is very similar to that of the United States,
British English (Commomwealth English) イギリス イングリッッシュ "Commonwealth English" is intended as a collective term for the perceived standard English language used in the Commonwealth of Nations1, applying in theory to Australian English, British English, Caribbean English, Canadian English, Hiberno-English (Irish English)2, Hong Kong English3, Indian English (includes Pakistani English), formal Malaysia English, New Zealand English, formal Singapore English (but not colloquial Singlish) and South African English. But Canadian English in particular does not fit well with the others.
The term is little used, and when used is most often synonymous with British English in its narrower sense or with International English in a specialized sense which excludes American English.