A Letter Concerning Toleration by John Locke (1689): A philosophical defense of religious freedom and the separation of church and state. It argued that civil government should not control religious belief. Thomas Jefferson and James Madison drew heavily on these ideas when shaping religious liberty principles in Virginia
Ab Urbe Condita (“From the Founding of the City”) by Livy (~27-9 BC): A monumental history of Rome that emphasized republican virtue, civic duty, and the dangers of corruption. John Adams and other founders used it as a moral and political guide for sustaining republics.
An Essay Concerning Human Understanding by John Locke (1690): Explores human knowledge as derived from experience (“tabula rasa”). Jefferson absorbed its empiricism, reinforcing Enlightenment confidence in reason and human progress.
Areopagitica by John Milton (1644): A passionate argument against censorship and for freedom of the press. Its defense of open discourse influenced American commitments to free expression in the First Amendment.
Cato’s Letters by John Trenchard and Thomas Gordon (1720-1723): A collection of essays published under the pseudonym “Cato,” these were wildly popular in colonial newspapers. They argued fiercely against political corruption, standing armies, and tyranny while championing freedom of speech and conscience. Benjamin Franklin and many colonial readers were deeply influenced by them.
Commentaries on the Laws of England by William Blackstone (1765 – 1769): A comprehensive explanation of English common law. This was the definitive legal bible for the founding generation. It shaped American understanding of the rule of law, due process, and individual liberty, which later formed the backbone of the Bill of Rights.
Common Sense by Thomas Paine (1776): A powerful pamphlet advocating independence from Britain and rejecting monarchy. Written in plain, scorching prose, this pamphlet was read by or to nearly every literate person in the colonies. It shattered the psychological tie to the British monarchy, arguing that a continent should not be governed by an island. It helped crystallize public opinion and directly paved the way for the Declaration of Independence.
De Officiis (“On Duties”) by Cicero (44 BC): A treatise on moral obligations and civic virtue. John Adams especially admired it and saw it as a guide for republican leadership and ethical public life.
De Jure Belli ac Pacis (“On the Law of War and Peace”) by Hugo Grotius (1625): A foundational work in natural law and international law. Influenced the Founders’ thinking on rights, sovereignty, and just conduct among nations.
Discourses Concerning Government by Algernon Sidney (1698): A republican critique of monarchy advocating popular sovereignty. Widely read in the colonies and influential on Jefferson and Adams.
Discourses on Livy by Niccolò Machiavelli (1517): Examines republican Rome and the maintenance of liberty through civic virtue. Helped shape Founders’ views on republics, corruption, and political stability.
Essays Moral, Political, and Literary by David Hume (1741–1758): Explores government, commerce, and human nature. Influenced Madison and others in understanding factions and political economy.
Histories (Book VI especially) by Polybius (~2nd century BC): An analysis of the Roman constitution and “mixed government.” Strongly influenced the structure of the U.S. Constitution (Senate, House, executive)
Institutes of the Lawes of England by Sir Edward Coke (1628–1644): Asserted that the king was subject to the law. Influenced colonial resistance to arbitrary authority.
Letters from a Farmer in Pennsylvania (1767–1768) by John Dickinson: A brilliant series of essays that united the colonies by arguing that British taxation without representation was unconstitutional. They were read by all the major figures and established the legal arguments used in the early stages of the resistance.
Letters On England (essays) by Voltaire: Religious liberty and free speech principles
Leviathan by Thomas Hobbes (1651): Argues for a powerful sovereign to prevent chaos. Though the Founders rejected its conclusions, its social contract framework shaped political debates they engaged with.
Magna Carta (anonymous charter – 1215): A foundational document limiting royal power and establishing legal rights such as due process. It strongly informed American legal traditions and constitutional protections.
Mayflower Compact by Pilgrim settlers (1620): An early agreement establishing self-government by consent. It served as a precedent for the idea of social contracts in America.
Moral Letters to Lucilius by Seneca (~65 AD): Stoic reflections on ethics and virtue. Influenced the Founders’ emphasis on personal discipline and republican virtue.
Notes on the State of Virginia by Thomas Jefferson (1785): Jefferson’s own reflections on government, society, and rights. Demonstrates how he combined Enlightenment, classical, and American influences.
Novanglus Essays by John Adams (1774–1775): A defense of colonial rights against British authority. Reflects Adams’ grounding in classical and English constitutional thought.
Parallel Lives by Plutarch (~1st century AD): Biographies comparing Greek and Roman leaders. A favorite of Washington and Adams, shaping their concepts of leadership and virtue. Plutarch’s biographies of Greek and Roman statesmen served as the ultimate guidebook on civic virtue, leadership, and the dangers of ambition.
Politics by Aristotle (~350 BC): Analysis of governmental forms and civic organization. Influenced the Founders’ understanding of republics and citizenship.
Poor Richard’s Almanack by Benjamin Franklin (1732–1758): A collection of maxims promoting thrift, hard work, and virtue. Shaped early American moral culture.
Principia Mathematica (1687) and Opticks (1704) by Sir Isaac Newton: Thomas Jefferson considered Newton, John Locke, and Francis Bacon to be “the three greatest men that have ever lived, without any exception.” Newton’s vision of a universe governed by rational, natural laws directly inspired the concept of “the Laws of Nature and of Nature’s God” invoked in the Declaration.
Second Treatise of Government by John Locke (1689): A foundational text arguing that governments exist to protect natural rights and derive authority from consent. Directly influenced Jefferson’s Declaration of Independence.
The Commonwealth of Oceana by James Harrington (1656): A republican vision emphasizing balanced government and land distribution. Influenced ideas of mixed government and constitutional design.
The English Bill of Rights (Parliamentary act) (1689): Established limits on monarchy and protected civil liberties. Directly shaped the U.S. Bill of Rights.
The Histories by Polybius: Polybius analyzed the structure of the Roman Republic, attributing its stability to a “mixed constitution” that combined elements of monarchy, aristocracy, and democracy. The Founders used this exact framework to build the system of checks and balances in the U.S. Constitution.
The History of the Decline and Fall of the Roman Empire (1776) by Edward Gibbon: Read closely by the Framers during and after the Constitutional Convention, Gibbon’s massive work served as a cautionary tale of how luxury, corruption, and overextended military power could destroy a free republic from within.
The History of the Peloponnesian War by Thucydides (~400 BC): A study of power, politics, and human nature. Influenced the Founders’ realism about conflict and governance.
The Holy Bible (King James Version) (translation 1611): A central moral and rhetorical influence. Its language and ethical framework permeate founding-era writings.
The Prince by Niccolò Machiavelli (1513): Analysis of political power and leadership. Though controversial, it influenced debates about realism vs virtue in governance.
The Republic by Plato (~380 BC): Explores justice and ideal government. While not directly adopted, it influenced philosophical discussions among educated founders.
The Social Contract by Jean-Jacques Rousseau (1762): Argues that legitimate authority comes from the people. Influenced ideas of popular sovereignty in American government. Widely read by Jefferson and Adams, Rousseau’s explorations of popular sovereignty and the “general will” fueled the foundational American belief that the people, not a monarch, hold ultimate power.
The Spirit of the Laws by Baron de Montesquieu (1748): If Locke inspired the Declaration, Montesquieu inspired the Constitution. He argued that to prevent tyranny, political power must be separated. The U.S. system of three distinct branches (Legislative, Executive, Judicial) with checks and balances is a direct implementation of Montesquieu’s theories. This work is a direct blueprint for the structure of the Constitution.
Two Treatises of Government by John Locke (1689): Unquestionably the most influential text for the Declaration of Independence. Locke’s concepts of “natural rights” (life, liberty, and property) and the “social contract”—the idea that government derives its legitimacy from the consent of the governed—were adapted almost word-for-word by Jefferson. See Second Treatise above; together they form the intellectual core of rights theory adopted by the Founders.
Tusculan Disputations by Cicero (45 BC): Philosophical discussions on ethics and happiness. Reinforced the moral philosophy underlying republican citizenship.
The Wealth of Nations by Adam Smith (1776): A foundational work in political economy advocating free markets. Published the exact same year as the Declaration, Smith’s critique of mercantilism and defense of free markets heavily influenced the economic philosophies of Alexander Hamilton and Benjamin Franklin.
Federalist Papers by Alexander Hamilton, James Madison, and John Jay (1787–1788): Essays defending the Constitution. They synthesize Enlightenment ideas (especially Montesquieu and Locke) into practical arguments for American government design.
The Autobiography of Benjamin Franklin by Benjamin Franklin (published posthumously, 1791): A narrative of self-improvement and civic virtue. Reflects Enlightenment ideals in practice.
The Federalist (see Federalist Papers)
Virginia Declaration of Rights by George Mason (1776): A declaration of inherent rights and government limits. Directly influenced Jefferson’s Declaration and the U.S. Bill of Rights.