Group Psychotherapy began in 1905 with Pratt who assembled tuberculosis patients for a class treatment. Application of psychoanalytic concepts to group psychotherapy varied from Pratt's rejection of Freud and psychoanalysis to Louis Wender's descriptive and educational use of psychoanalysis in his group psychotherapy in 1936. At about the same time (1936) Paul Schilder actually interpreted the resistance, transferences, and dreams in his group psychotherapy sessions. Accordingly, Schilder would have to be recognized as the first to conduct a psychoanalytic group psychotherapy. Schilder's many contributions to group psychotherapy appeared in a few papers written before 1941. Precursors of current mainstream group psychotherapy can be found in them and they are still used as references.