Roger Williams argued for a separation of church and state in the 17th century, believing that government and religion should remain separate. He was exiled for his ideals but went on to found Rhode Island based on principles of religious freedom. His writings inspired figures like Jefferson and Madison, and the First Amendment enshrines separation of church and state by prohibiting the establishment of an official state religion. However, some laws today that promote specific religious values over others have been challenged as unconstitutional. There continues to be debate around how strictly to interpret the separation of church and state.