Does american english has deviated much from british english?
It's American English a dialect of British English
Has american english deviated much from british english?
No, because American English didn't come form british english. Both came from Old English.
No, because American English didn't come form british english. Both came from Old English.
Technically, Old English was a form of British English, but both American English and Modern British English came from Old English, American English didn't come from Modern British English.