first attestation of the plural "Americas" in English?

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Hello. In current parlance, we see the plural form "Americas" used typically with the definite article, "the Americas". (I'm not posting examples, because they are countless and easily discovered.) It is variously defined as "North and South America", "North, Central, and South America", "..plus the Caribbean", "the New World", "the Western Hemisphere" (but presumably not bits of Antarctica), and so on.

But, does the term "Americas" in the plural go back to the Age of Discovery, or is it a relatively recent coinage? When was it first used in English, and was the meaning close to the way it is now used? Here's ngrams for Americas.