The U.S. Coast Guard operates under the U.S. Department of Homeland Security during peacetime. During times of war, it can be transferred in whole or in part to the U.S. Department of the Navy under the Department of Defense by order of the U.S. president or by act of Congress. Prior to its transfer to Homeland Security, it operated under the Department of Transportation from 1967 to 2003 and the Department of the Treasury from its inception until 1967.[12][13] A congressional authority transfer to the Navy has only happened once: in 1917, during World War I.[14] As for World War II, the U.S. Coast Guard was transferred to the Navy by President Franklin Roosevelt one month before the country's entry into the war.[15]