As secretary, Calhoun had responsibility for the management of Indian affairs. He promoted a plan, adopted by Monroe in 1825, to preserve the sovereignty of eastern Indians by relocating them to western reservations they could control without interference from state governments. In over seven years Calhoun supervised the negotiation and ratification of 40 treaties with Indian tribes. Calhoun opposed the invasion of Spanish Florida launched in 1818 by General Jackson during the First Seminole War, which was done without direct authorization from Calhoun or President Monroe, and in private with other cabinet members, advocated censuring of Jackson as punishment. Calhoun claimed that Jackson had begun a war against Spain in violation of the Constitution and, falsely, that he had contradicted Calhoun's explicit orders in doing so. No official instructions not to invade Florida or attack the Spanish were ever issued by the administration. However, Calhoun supported the execution of Alexander Arbuthnot and Robert Ambrister, two British soldiers living in Florida who were accused of inciting the Seminole to make war against the United States. Calhoun accused the British of being involved in "wickedness, corruption, and barbarity at which the heart sickens and which in this enlightened age it ought not scarcely to be believed that a Christian nation would have participated". He added that he hoped the executions of Arbuthnot and Ambrister would deter the British and any other nations "who by false promises delude and excite an Indian tribe to all the deeds of savage war". The United States annexed Florida from Spain in 1819 through the Adams–Onís Treaty.