Within the New World during the early 19th century, most of the nations of Spanish America achieved independence from Spain. The United States supported that status, as policy in the hemisphere relative to European colonialism, with the Monroe Doctrine. The American public, organized associated groups, and Congressional resolutions, often supported such movements, particularly the Greek War of Independence (1821–29) and the demands of Hungarian revolutionaries in 1848. Such support, however, never became official government policy, due to balancing of other national interests. After the American Civil War and with increasing capability, the United States government did not accept self-determination as a basis during its Purchase of Alaska and attempted purchase of the West Indian islands of Saint Thomas and Saint John in the 1860s, or its growing influence in the Hawaiian Islands, that led to annexation in 1898. With its victory in the Spanish–American War in 1899 and its growing stature in the world, the United States supported annexation of the former Spanish colonies of Guam, Puerto Rico and the Philippines, without the consent of their peoples, and it retained "quasi-suzerainty" over Cuba, as well.