Amann was sentenced to ten years in a labour camp and stripped of his property, pension rights, and virtually all of his fortune.

After attending volksschule and a business school, he worked for a few years as a commercial office apprentice and a salesman.

When the First World War broke out he was transferred to the 16th Royal Bavarian Infantry Regiment and obtained the rank of Feldwebel (equivalent to the US Army staff sergeant).

Amann took part in the November 1923 Beer Hall Putsch and in April 1924 was sentenced to four-and-a-half months in Landsberg Prison.

[5] Amann's most notable contribution was persuading Hitler to retitle his first book from Viereinhalb Jahre (des Kampfes) gegen Lüge, Dummheit und Feigheit, ("Four and a Half Years (of Struggle) Against Lies, Stupidity and Cowardice") to Mein Kampf, ("My Struggle") which he also published.

Amann joined the SS on 15 March 1932 with the rank of SS-Gruppenführer, was promoted to SS-Obergruppenführer on 30 January 1936 and was assigned to the staff of the Reichsführer-SS.

Poor handwriting can be attributed in part to the loss of his left arm in an accident with a firearm while hunting with Franz Ritter von Epp on 4 September 1931.

[11] Arrested by American troops after the war ended, Amann was deemed a Hauptschuldiger (Major Offender) and sentenced to ten years in a labour camp on 8 September 1948.

[15] The German Lost Art Foundation listed the 10 paintings and 4 sculptures, which included works from Gabriel Mäleßkircher,[16][17] Franz von Stuck,[18] Friedrich Kaulbach[19] and others, in the lostart.de database.