Franklin D. Roosevelt was appointed Assistant Secretary of the Navy by Woodrow Wilson in 1913. He served under Secretary of the Navy Josephus Daniels. In 1914, he was defeated in the Democratic primary election for the United States Senate by Tammany Hall-backed James W. Gerard. As assistant secretary, Roosevelt worked to expand the Navy and founded the United States Navy Reserve. Wilson sent the Navy and Marines to intervene in Central American and Caribbean countries. In a series of speeches in his 1920 campaign for Vice President, Roosevelt claimed that he, as Assistant Secretary of the Navy, wrote the constitution which the U.S. imposed on Haiti in 1915.
Roosevelt developed a life-long affection for the Navy. Roosevelt negotiated with Congressional leaders and other government departments to get budgets approved. He became an enthusiastic advocate of the submarine and of means to combat the German submarine menace to Allied shipping: he proposed building a mine barrier across the North Sea from Norway to Scotland. In 1918, he visited Britain and France to inspect American naval facilities; during this visit he met Winston Churchill for the first time. With the end of World War I in November 1918, he was in charge of demobilization, although he opposed plans to completely dismantle the Navy. In July 1920, Roosevelt resigned as Assistant Secretary of the Navy.