 These claims were eventually withdrawn by France, formalized in a proclamation dated August 5, 1845, turning over full sovereignty of the island to Spain.During the same year, a US survey mission studied the potentials of the Sulu archipelago, but American intervention did not start until 1899.After two centuries of incessant and unrelenting raids and counter-raids, the fortunes of the Spanish Empire in the Sulu Archipelago took a dramatic turn for the better in 1848, primarily due to three watershed events