When he was 21, Selfridge went to Chicago. He worked for Field, Leiter and Company. This later became Marshall Field's & Co. He worked there for 25 years. Selfridge started the idea of a bargain basement in a department store. Selfridge's ideas added to the success of Marshall Field & Company. When he asked Marshall Field to let him become a partner, Field was surprised, but he agreed. Field even lent him the money needed to become a partner.