"Hermit Author of Palo Alto"
Though I couldn't find 
any real documentation for why Hoover was given this nickname... [DOC] [TLE] Herbert Hoover Biography - Childhood, Life Achievements & Timeline [PAR] The Hermit Author of Palo Alto, Herbert Clark Hoover, Friend of Helpless 
Children, The Grand Old Man, The Man of Great Heart, Herbert C Hoover.