Bormann's studies at an agricultural trade high school were interrupted when he joined the 55th Field Artillery Regiment as a gunner in June 1918, in the last days of World War I. He never saw action, but served garrison duty until February 1919. After working a short time in a cattle feed mill, Bormann became estate manager of a large farm in Mecklenburg. Shortly after starting work at the estate, Bormann joined an antisemitic landowners association. While hyperinflation in the Weimar Republic meant that money was worthless, foodstuffs stored on farms and estates became ever more valuable. Many estates, including Bormann's, had "Freikorps" units stationed on site to guard the crops from pillaging. Bormann joined the "Freikorps" organisation headed by Gerhard Roßbach in 1922, acting as section leader and treasurer.