How common are two pin electric plug sockets vs three pin in the US of A? : AskAnAmerican(00)

How common are two pin electric plug sockets vs three pin in the US of A? : AskAnAmerican(00)

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How common are two pin electric plug sockets vs three pin in the US of A? : AskAnAmerican Plug & socket types Map showing the spread of the different plug types worldwide