- Founding of Providence: Roger Williams is primarily known for founding Providence, Rhode Island. He established this colony in 1636 after facing religious persecution in the Massachusetts Bay Colony. Providence was founded on principles of religious freedom and separation of church and state, becoming one of the first such settlements in North America.
- Advocacy for Religious Freedom: Williams was a strong advocate for religious freedom and believed in the separation of church and state. He argued against the Puritan practice of requiring religious uniformity and asserted the right of individuals to worship according to their own beliefs. This stance led to his banishment from the Massachusetts Bay Colony.
- Theological Writings: Williams was also a prolific writer and theologian. His most notable works include "The Bloody Tenet of Persecution" (1644) and "George Fox Digged Out of His Burrowes" (1676), in which he expounded on his beliefs and defended religious toleration.
- Influence on American Democracy: Williams's ideas on religious freedom and the separation of church and state had a significant impact on the development of American democracy. These principles were later incorporated into the First Amendment of the United States Constitution, which protects the free exercise of religion.