 In 1944, he died while visiting another daughter in St. Petersburg, Florida.A collection of his papers is held at the University of California, Riverside, including correspondence related to his obtaining permission to remain in Banning during the war.The following biography of Sadakichi Hartmann is taken from Paul Avrich's "The Modern School Movememnt" from page 134-138

"Next to Havel, the most exotic personality at the Ferrer Center was Sadakichi Hartmann.