The early modern period was transformed by revolutions in thought and governance. The Scientific Revolution (16th–18th century) brought major advances in physics, astronomy, biology, and chemistry, as figures like Copernicus, Galileo, Kepler, and Newton replaced medieval theories with evidence-based science. Building on this, the Enlightenment (17th–18th century) was an intellectual movement emphasizing reason, individual liberty, and skepticism of authority. Thinkers like John Locke (1632–1704), who argued for natural rights including life, liberty, and property, and government by consent of the governed, profoundly influenced the American and French Revolutions and modern political thought.
These ideas fueled political upheaval on both sides of the Atlantic. The French Revolution (1789–1799) overthrew the monarchy, established a republic, and proclaimed the ideals of liberty, equality, and fraternity. However, its radical phase included the Reign of Terror (1793–1794), led by Maximilien Robespierre and the Committee of Public Safety, during which thousands were executed by guillotine as suspected enemies of the revolution. Napoleon Bonaparte (1769–1821), a French military leader, then rose to become Emperor and conquered much of Europe. His Napoleonic Code reformed legal systems across the continent, and his wars reshaped European borders and politics. After his defeat, the Congress of Vienna (1814–1815) redrew European boundaries, aiming to restore a balance of power and monarchies that shaped European politics for decades.
Across the Atlantic, Enlightenment ideals inspired the Latin American independence movements of the early 19th century, in which colonies revolted against Spanish and Portuguese rule. Leaders like Simón Bolívar (1783–1830), known as "El Libertador," liberated Venezuela, Colombia, Ecuador, Peru, and Bolivia from Spanish rule and envisioned a unified Latin America. At the same time, the 19th century saw a growing global movement to abolish slavery: Britain ended the slave trade in 1807 and slavery itself in 1833; the United States abolished it in 1865 with the 13th Amendment; and Brazil, the last Western Hemisphere nation to do so, ended it in 1888. Together, these revolutions challenged traditional hierarchies and laid the intellectual and political foundations of the modern world.