(January 9, 1724–November 20, 1806), was an American separatist leader and colonial historian. He wrote many influence works, including: History of New England—with Particular Reference to the Denomination of Christians Called Baptist, published in 1777; and “A Declaration of the Rights of the Inhabitants of the State of Massachusetts-Bay in New England," in which he stated:
Nothing can be true religion but a voluntary obedience unto His revealed will, of which each rational soul has an equal right to judge for himself, every person has an unalienable right to act in all religious affairs according to the full persuasion of his own mind.649
In September of 1775, Isaac Backus spoke to the Massachusetts Assembly, in behalf of the Warren Association, on the subject of taxing religious dissenters:
Is not all America now appealing to Heaven against the injustice of being taxed where we are not represented, and against being judged by men who are interested in getting away our money? And will heaven approve your doing the same thing to your fellow servants? No, surely. …
Yet, as we are persuaded that an entire freedom from being taxed by civil rulers to religious worship is not mere favor from any men in the world but a right and property granted us by God, who commands us to stand fast in it, we have not only the same reason to refuse an acknowledgement of such a taxing power here, as America has the above said power, but also, according to our present light, we should wrong our consciences in allowing that power to men, which we believe belongs only to God.650