The Empire of Liberty is a theme developed first by Thomas Jefferson to identify the responsibility of the United States to spread freedom across the world. Jefferson saw the mission of the U.S. in terms of setting an example, expansion into western North America, and by intervention abroad. Major exponents of the theme have been Abraham Lincoln (in the Gettysburg Address), Theodore Roosevelt, Woodrow Wilson (and "Wilsonianism"), Franklin D. Roosevelt, Harry Truman, Ronald Reagan, Bill Clinton, and George W. Bush.
In the History of U.S. foreign policy the Empire of Liberty has provided motivation to fight the Spanish–American War (1898), World War I (1917), the later part of World War II (1941), the Cold War (1947–91) and the War on Terror (2001–present).
Jefferson used this phrase "Empire of Liberty" in 1780, while the American revolution was still being fought. His goal was an empire dedicated to liberty that could stop the growth of the British Empire, which he hated and feared:
"We shall divert through our own Country a branch of commerce which the European States have thought worthy of the most important struggles and sacrifices, and in the event of peace [ending the American Revolution]...we shall form to the American union a barrier against the dangerous extension of the British Province of Canada and add to the Empire of liberty
an extensive and fertile Country thereby converting dangerous Enemies into valuable friends." — Jefferson to George Rogers Clark, 25 December 1780
Jefferson envisaged this "Empire" extending Westwards over the American continent, expansion into which he saw as crucial to the American future. During his Presidency, this was in part achieved by his 1803 purchase of the Louisiana Territory from the French, almost doubling the area of the Republic and removing the main barrier to Westward expansion, stating that "I confess I look to this duplication of area for the extending of a government so free and economical as ours, as a great achievement to the mass of happiness which is to ensue".
However, this was not necessarily a politically unified Empire. "Whether we remain in one confederacy, or form Atlantic and Mississippi confederacies, I believe not very important to the happiness of either part." Despite this, Jefferson on other occasions seemed to stress the territorial inviolability of the Union.
In 1809 Jefferson wrote his successor James Madison:
"we should then have only to include the North [Canada] in our confederacy...and we should have such an empire for liberty as she has never surveyed since the creation: & I am persuaded no constitution was ever before so well calculated as ours for extensive empire & self government." — Jefferson to James Madison, 27 April 1809
Even in his later years, Jefferson saw no limit to the expansion of this Empire, writing "where this progress will stop no-one can say. Barbarism has, in the meantime, been receding before the steady step of amelioration; and will in time, I trust, disappear from the earth".
The Monroe Doctrine, a U.S. foreign policy initiative introduced in 1823, states that efforts by European countries to colonize or interfere with states in the Americas would be viewed as acts of aggression requiring U.S. intervention. Its justification was to make the New World safe for liberty and American-style republicanism, as well as prevent the further growth of European empires in the New World. The Monroe Doctrine was invoked against the takeover of Mexico by France (1860s) and Imperial Germany (see Zimmermann Telegram 1917). After 1960 the Monroe Doctrine was invoked to roll back Communism from its new base in Castro's Cuba. Ronald Reagan, emphasized the need to rollback Communism in Nicaragua and Grenada.
American Protestant and Catholic religious activists began missionary work in "pagan" areas from the 1820s, and expanded operations worldwide in the late 19th century.
European nations (especially Britain, France and Germany) also had missionary programs. The Europeans focused mostly on their own empires. Americans went anywhere it was possible, and had no government funding. The Young Men's Christian Association (YMCA) and Young Women's Christian Association (YWCA) were among the many groups involved in missionary work. Others included the student volunteer movement and the King's Daughters. Among Catholics, the three Maryknoll organizations were especially active in China, Africa, and Latin America.
Religious reform organizations joined in attempts to spread modernity and worked to fight the corrupting effects of ignorance, disease, opium and alcohol. For example, the World's Woman's Christian Temperance Union (WWCTU), a spinoff of the WCTU, had both strong religious convictions and a commitment to international efforts to shut down the liquor trade. By the 1930s the more evangelical Protestant groups redoubled their efforts, but the more liberal Protestants had second thoughts about their advocacy, especially after the failure of prohibition at home cast doubt on how easy it might be to reform the world.
Economic dimensions of the Empire of Liberty involved dissemination of American management methods (such as Taylorization, Fordism, and the assembly line), technology, and popular culture such as film.
George Washington, the first United States president, said in his Farewell Address that the country should avoid interfering in foreign affairs, especially those of Europe, for having have little or nothing to do with the national interests.
The Monroe Doctrine stated that the United States should prevent European countries from interfering with states in the Americas, but should not interfere with European countries or colonies.
The Irreconcilables were a group of senators who opposed the ratification of the Treaty of Versailles in 1919, which compelled the country to defend other nations.
In the 1930s, the Congress passed the Neutrality Acts, which attempted to avoid entering in conflicts with other nations. The United States became involved in World War II two years after its start.
Writers on the Left often capitalized on anti-imperialism by using the label American Empire in a negative sense. Noam Chomsky and Chalmers Johnson are prominent spokesmen for this position. Their argument is that an America empire represents an evil, and indeed the very thing that the "Empire of Liberty" was conceived to counter, imperialism. They recommend dismantling the empire. Puerto Rican poet and novelist Giannina Braschi proclaims the collapse of the World Trade Center as the end of the American Empire and its colonial hold on Puerto Rico in her post 9-11 work "United States of Banana" (2011).