This question would require an answer of several pages. Although a great starting point would be the discussion of two men, Roger Williams and William Penn.
Roger Williams was persecuted greatly due to his
religious views in Massachusetts and so he founded Rhode Island. He advocated
religious freedom which authorized the Jews to enter Rhode Island and establish
the city of Newport. Rhode Island religious independence is also the foundation
of the First Amendment.
William Penn also endorsed religious freedom for other
religions. The Quakers were persecuted in England and Penn helped their massive
migration to Pennsylvania. He, who is like Williams, also promoted religious tolerance.
Penn also promoted equal treatment of the Indians.