How did American English change in the modern era?

The custom of the English Language in the US was a result of British colonization, which commenced in North America in the 17th century The American accent was influenced by immigrants and British colonizers. The evolution of spoken English began from the fifth century, with waves of attack and eventual occupation by the Angles, Saxons, Jutes and Frisians. The spoke the same West Germanic Tongue but with different dialects.

Presents linguistic evidence does not support the notion of there being one single mainstream American accent that spoken American English did not simply deviate away from period British English.