Considered a leading orator of the "pulpit of the American Revolution", Backus published a sermon in 1773 that articulated his desire for religious liberty and a separation of church and state. Called An Appeal to the Public for Religious Liberty, Against the Oppressions of the Present Day, in it Backus stated: "Now who can hear Christ declare, that his kingdom is, not of this world, and yet believe that this blending of church and state together can be pleasing to him?"
In 1778, he authored a historically important work entitled Government and Liberty Described and Ecclesiastical Tyranny Exposed of which a copy is held by the John Carter Brown Library at Brown.
Allison, William Henry. "Isaac Backus." Dictionary of American Biography. Vol I., p. 471. New York: Charles Scribner's Sons, 1928, 1943.
Backus, Isaac. A History of New England with Particular Reference to the Denomination of Christians Called Baptists. 2nd ed, with notes by David Weston. 2 vols. Newton, Massachusetts: Backus Historical Society, 1871.
The Diary of Isaac Backus. William G. McLoughlin, ed. 3 vol. Providence: Brown University Press, 1979.
Grenz, Stanley J. "Church and State: The Legacy of Isaac Backus." Center Journal 2 (Spring 1983): 73-94.
"Isaac Backus: Eighteenth Century Light on the Contemporary School Prayer Issue." Perspectives in Religious Studies 13 (Winter, 1986): 35-45.
"Isaac Backus and Religious Liberty." Foundations 22 (October/December 1979): 352-360.
Isaac Backus, Puritan and Baptist: His Place in History, His Thought, and Their Implications for Modern Baptist Theology. Macon, GA: Mercer University Press, 1983.
Hovey, Alvah. A Memoir of the Life and Times of the Rev. Isaac Backus, A.M. Boston: Gould and Lincoln, 1859.