In 1823, the fifth American President James Monroe (1758–1831, served 1817–25) enunciated the Monroe Doctrine, which stated that the United States would not tolerate further efforts by European governments to retake or expand their colonial holdings in the Americas or to interfere with the newly independent states in the hemisphere. The U.S. would, however, respect the status of the existing European colonies. Before the American Civil War (1861–1865), Southern interests attempted to have the United States purchase Cuba and convert it into a new slave state. The pro-slavery element proposed the Ostend Manifesto proposal of 1854. Anti-slavery forces rejected it.