Congress of Industrial Organizations http://www.encyclopedia.chicagohistory.org/pages/326.html http://www.encyclopedia.chicagohistory.org/pages/326.html http://www.encyclopedia.chicagohistory.org/pages/326.html Congress of Industrial Organizations http://www.encyclopedia.chicagohistory.org/pages/326.html http://www.encyclopedia.chicagohistory.org/pages/326.html Congress of Industrial Organizations