Isaac Backus (1724-1806), born in Norwich, Conn., was a Baptist leader in colonial America and a defender of religious freedom. He became a Christian in 1741 during the Great Awakening. He became a Baptist in 1751, founded a Baptist congregation at Middleboro, Mass. in 1756 and served as its pastor until his death. Backus was a noted proponent of "separation of church and state" and on this issue voted to ratify the U.S. Constitution at the Massachusetts ratifying convention in 1788. He died in Middleboro on Nov. 20, 1806.
He lived at a time when the Congregationalist church was the official, state-supported church in Massachusetts. He waged a long fight for the rights of dissenting religion in New England. He attacked the established status of the Congregational Church which ‑ even in the days of the Revolution ‑ continued to tax and fine and jail those who declined to support the state church.
He argued that state-support for a church only ended up corrupting true Christianity. When all America was alarmed about a tax on tea, Backus wrote, "Should not a tax on liberty of conscience be even more an occasion of revulsion and revolt? Should we win independence from England only to surrender it to a privileged and persecuting elite at home?" 
He became a leading spokesman for the Baptist church and wrote A History of New England, with Particular Reference to the Denomination of Christians Called Baptists (1777–96), a major source for the religious history of the region and the period.
- Isaac Backus (and David Weston), History of New England Baptists: With Particular Reference to the Denomination of Christians Called Baptists, Baptist Standard Bearer; 2nd edition (March 2001). ISBN 1579789188
- Stanley Grenz, Isaac Backus - Puritan and Baptist: his place in history, his thought, and their implications for modern Baptist theology, Macon, Ga.: Mercer University Press, 1983. ISBN 0865540675
- William G. McLoughlin, Isaac Backus and the American Pietistic Tradition, Little Brown & Company (1967). ISBN 0316562181
- Alvah Hovey, Memoir of the Life and Times of the Reverend Isaac Backus (The Era of the American Revolution), Da Capo Pr (February 1972). ISBN 0306704153