In 1643, Roger Williams wrote A Key Into the Language of America, A help to the language of the natives in that part of America called New England. He wrote the book mostly while on the two-month voyage to England. It was on sale by September 7, 1643.

He wrote down what he learned about the Narragansett culture and language. This 17th century book describes the Native American languages in the New England area (largely Narragansett, an Algonquian language). At the time of this book, New England consisted of the Massachusetts, Rhode Island, Connecticut, and New Hampshire colonies.