system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How did American accents "develop"? When the Americas were first discovered the people who immigrated (from England) spoke English with a British accent. How did it "become" American English?

I've always wanted to know the answer to this question and no one has ever seemed to have it; hopefully I'll have luck in the reddit community!
gpt
Both the modern dominant British accent, and the modern dominant American accent are different from the accent used during the colonial era. They both also have different features from that earlier accent that they held onto. Some linguists believe the American accent is "closer" to the colonial era dominant accent but there is debate about it. 

As to how/why the accents developed, that happened for the same reason all accents develop. Certain speaking habits get passed on and emphasized within a given community or region until they become distinct from other regions within the same language.