the "backyard".
Monroe Doctrine's Background:
At the Congress of Verona, held from mid-October to 14 December 1822 [which is usually interpreted as the last meeting of the Holy European Alliance, initially constituted in Paris on 26 September 1815 between the King of Prussia and the Emperors of Austria and Russia], it was decided to help the re-establishment of absolutism in Spain, facilitating Ferdinand VII to regain power with the help of the One Hundred Thousand Sons of San Luis who put an end to the liberal triennial, after a new French military occupation of Spain (April to October 1823). Fearful of a Franc-Spanish absolutist offensive in the Spanish-American republics that during the Spanish liberal triennial had advanced in their national consolidation, the British Foreign Minister, Jorge Canning, proposed to the American ambassador in London, Ricardo Rush, a joint declaration that would stop such potential intervention:
https://www.theodorerooseveltcenter.org/Research/Digital-Library/Record?libID=o25467
Thomas Jefferson, who was the third president of the United States (from 1801 to 1809), friend for decades of the then president, Monroe, addressed to him on October 24, 1823 a letter that translated says:
https://founders.archives.gov/documents/Jefferson/01-35-02-0550
The "Monroe Doctrine" and its transformations:
Over time, the Monroe doctrine, which had become a political program for the United States abroad, popularized in the synthetic formula "America for Americans", had to be transformed and adapted to new political and historical realities. The great Mexican historian Carlos Pereyra, in The Myth of Monroe, assures that there is no Monroe doctrine, since there are at least three "Monroe doctrines" that he differentiated (in 1916).
From 1869, it was also associated with another point, contained in previous diplomatic correspondence: the United States opposes the transfer of colonies from one European power to another.
In his message to Congress on December 6, 1904, President Theodore Roosevelt proclaimed what is known as the "Roosevelt corollary," which is rather an amendment to doctrine, determined by the debt payments crisis to European banks by some American nations and attempts to use force by European powers to obtain payment: the United States could intervene in the nations of the hemisphere, to control this "chronic evil", acting as "international police", commonly known as the "big stick" policy.
U.S. half-dollar coin minted to celebrate the centennial of the Monroe Doctrine: "United States of America. In God we trust. 1923. Monroe & Adams. Half Dollar / Monroe Doctrine Centennial. Los Angeles 1823-1923." Note the significant and not naïve substitution that has occurred in the allegory of the two Americas, which comes from the emblem, two women shaking arms in Central America, adopted by the Pan-American Exposition of 1901, designed by Rafael Beck (1859-1947), winner of the contest convened for this purpose in 1899: the artist of the commemorative coin of the centenary celebrated in 1923 has preferred to replace the lady who represented Hispanic America with the image of an indigenous, in full rise the ideology that sought to dissolve Hispanism into indigenism.