Until the end of the nineteenth century, the United States had a special relationship primarily with nearby Mexico and Cuba. Otherwise, relationships with other Latin American countries were of minor importance to both sides, consisting mostly of a small amount of trade. Apart from Mexico, there was little migration to the United States, and little American financial investment. Politically and economically, Latin America (apart from Mexico and the Spanish colony of Cuba) was largely tied to Britain. The United States had no involvement in the process by which Spanish possessions broke away and became independent around 1820. In cooperation with and help from Britain, the United States issued the Monroe Doctrine in 1823, warning against the establishment of any additional European colonies in Latin America.