The place of slavery in the westward expansion of the nation was not the only burning question which the American people had to face in the presidency of Monroe. Within a few years after that contest, the problem of the independence of the New World and of the destiny of the United States in the sisterhood of new American republics confronted the administration. Should the political rivalries and wars of Europe to acquire territory be excluded from the western hemisphere? Should the acquisition of new colonies by European states in the vast unsettled spaces of the two Americas be terminated? These weighty questions were put to the mild Virginian statesman; history has named his answer the Monroe Doctrine.

From the beginning of our national existence, the United States had been pushing back Europe from her borders, and asserting neutrality and the right to remain outside of the political System of the Old World. Washington's farewell address of 1796, with its appeal to his fellow-citizens against "interweaving our destiny with that of any part of Europe," sank deep into the popular consciousness. It did not interfere with the process by which, piece by piece, the United States added to its domains fragments from the disintegrating Spanish empire; for so long as European states held the strategic positions on our flanks, as they did in Washington's day, the policy of separation from the nations of the Old World was one difficult to maintain; and France and England watched the enlargement of the United States with jealous eye. Each nation, in turn, considered the plans of Miranda, a Venezuelan revolutionist, for the freeing of Spanish America. In 1790 the Nootka Sound affair threatened to place England in possession of the whole Mississippi valley and to give her the leadership in Spanish America. [Footnote: Turner, in Am. Hist. Rev., VII., 704, VIII., 78; Manning, Nootka Sound Controversy, in Am. Hist. Assoc., Report, 1904, p. 281; cf. Bassett, Federalist System (Am. Nation, XI), chap. vi.] Two years later, France urged England to join her in freeing the colonies of Spain in the New World;[Footnote: Sorel, L'Europe et la Revolution Francaise, II., 384, 418, III., 17.] and when Pitt rejected these overtures, France sent Genet to spread the fires of her revolution in Louisiana and Florida.[Footnote: Turner, in Am. Hist. Rev., III., 650, X. 259.] When this design failed, France turned to diplomacy, and between 1795 and 1800 tried to persuade Spain to relinquish Florida and Louisiana to herself, as a means of checking the expansion of the United States and of rendering her subservient to France. The growing preponderance of France over Spain, and the fear that she would secure control of Spanish America, led England again in 1798 to listen to Miranda's dream of freeing his countrymen, and to sound the United States on a plan for joint action against Spain in the New World. [Footnote: Turner, in Am. Hist. Rev., X., 249 et seq., 276.] The elder Adams turned a deaf ear to these suggestions, and when at last Napoleon achieved the possession of Louisiana, it was only to turn it over to the United States. [Footnote: Sloane, in Am. Hist. Rev., IV., 439.] Jefferson's threat that the possession of Louisiana by France would seal the union between England and the United States and "make the first cannon which shall be fired in Europe the signal for the tearing up of any settlement she may have made, and for holding the two continents of America in sequestration for the common purposes of the united British and American nations," [Footnote: Jefferson, Writings (Ford's ed.), VIII., 145.] showed how unstable must be the American policy of isolation so long as Europe had a lodgment on our borders. [Footnote: Cf. Channing, Jeffersonian System (Am. Nation, XII.), chap. v.]

The acquisition of Louisiana by the United States was followed by the annexation of West Florida; and the Seminole campaign frightened Spain into the abandonment of East Florida. [Footnote: Babcock, American Nationality (Am. Nation, XIII.), chap. xvii.] While the United States was thus crowding Europe back from its borders and strengthening its leadership in the New World, Spanish America was revolting from the mother-country. When Napoleon made himself master of Spain in 1807, English merchants, alarmed at the prospect of losing the lucrative trade which they had built up in the lands which Spain had so long monopolized, supported the revolutionists with money, while various expeditions led by English officers aided the revolt. [Footnote: Paxson, Independence of the So. Am. Republics, chap, iii.; Am. Hist. Rev., IV., 449, VI., 508.] At first, failure met the efforts of the loosely compacted provinces, made up of sharply marked social classes, separated by race antagonisms, and untrained in self-government. Only in Buenos Ayres (later the Argentine Confederation), where representatives of the United Provinces of the Rio de la Plata declared their independence in 1816, were the colonists able to hold their ground.