He joined the SPD in 1919 .
Hinrich Wilhelm Kopf ( 6 May 1893 -- 21 December 1961 ) was a German politician ( SPD ) .
Hinrich Wilhelm Kopf joined the SPD in 1919 .
Hinrich Wilhelm Kopf ( 6 May 1893 -- 21 December 1961 ) was a German politician ( SPD ) .