Henry Clay, William Branch Giles (1827). “Mr. Clay's Speech on the Tariff: Or, The "American System," So Called ; Or, The Anglican System, in Fact, Introduced Here ; and Perverted in Its Most Material Bearing Upon Society, by the Omission of a System of Corn Laws, for the Protection of Agriculture”, p.80
Henry Clay (2015). “The Papers of Henry Clay: Candidate, Compromiser, Elder Statesman, January 1, 1844-June 29, 1852”, p.553, University Press of Kentucky