After a two year effort by Secretary of the Navy Josephus Daniels and his assistant, a young New Yorker named Franklin D. Roosevelt, the Navy Reserves were officially established 3 March 1915, as the Naval Reserve Force, fundamentally (but not totally) replacing the patchwork series of state naval militias of part-time bluejackets who trained on loaned surplus U.S. Navy warships.
The USNR’s history has been impressive ever since, including more than 3.5 million officers and Sailors on the service’s rolls during WWII (84 percent of the Navy as a whole) to count five future U.S. presidents.