Why there are some differences between British English and American English?

Question

For example: Center is American, Centre is British.

Answer 1

American English is a bastardization of the Queens English... main differences are spelling and pronounciation.. either are accepted as correct... I suppose you could call it the vernacular... in parts of Britian the word aluminum is pronounced alu-min-ium and laboratory is pronounced lab-ra-tory in America...I guess you could say, po-TAE-toe/ po-TAH-toe.
I am Canadian and I still speak and spell the Queens English even though I reside in America ( to the bane of the Americans around me). It's not a matter of snobbishness but, rather, I believe it sounds more favourable to the ear.
Another example is the letter "Z"... I say "ZED" rather than "ZEE"... I feel it is easier to decern it from the sound of the letter "C", especially when, for example, spelling something over the telephone amking the intended letter easier to decern.
Another is the word "BASIL". When referrencing the herb I pronounce it "BAE-SL" and when saying the name I pronounce it "BAH-SL".
It all boils down to preference and possibly to differentiate and distance America from Britain after the Revolutionary War.

Answer 2

Pronunciation and spelling. U.S. is "while" British is "whilst." U.S. pronounces geyser as "gi ser" , British "geeser." U.S. lichen pronounced "like en" British "litchen."
U.S. spelling "tire" British "tyre."
Some of the U.S. pronunciations have come from linguistical influences other than the English language. Also, in the U.S., there are various regional pronunciations. In the northwest, we pronounce wolf as it is spelled, other areas say "woof." In some areas coyote is pronounce "ky o tee." In the Northwest, many people pronounce it "ky oat" and some Canadians say "ky oot."
Can be a bit confusing at times.

Answer 3

armor armour
gray grey
elevator lift
subway underground

Answer 4

Just philosophy!!