History.com says "The political and religious leader Roger Williams (c. 1603? -1683) is best known for founding the state of Rhode Island and advocating separation of church and state in Colonial America. He is also the founder of the First Baptist Church in America. His views on religious freedom and tolerance, coupled with his disapproval of the practice of confiscating land from Native Americans, earned him the wrath of his church and banishment from the Massachusetts Bay Colony. Roger Williams and his followers settled on Narragansett Bay, where they purchased land from the Narragansett Indians and established a new colony governed by the principles of religious liberty and separation of church and state. Rhode Island became a haven for Baptists, Quakers, Jews, and other religious minorities. Nearly a century after his death, Williams’ notion of a “wall of separation” between church and state-inspired the founders of the United States, who incorporated it into the U.S. Constitution and Bill of Rights."
here is the link. It's in the first paragraph https://www.history.com/topics/reformation/roger-williams
