(Just to clarify, I do not mean to insinuate that these were his only inspirations; they most certainly weren’t, as anybody who regularly reads this subcommunity can attest.)

Quoting Carroll P. Kakel’s The Holocaust as Colonial Genocide: Hitler’s ‘Indian Wars’ in the ‘Wild East’, pages 17–8:

During his youth, Hitler had been fascinated by the ‘American West’, its ‘frontier’, and its hardy pioneer settlers. His initial awareness of the ‘Wild West’ and the American assault on ‘native’ indigenous populations came from his lifelong reading (and rereading) of Karl May, the German cowboy Western novelist who wrote about the American frontier.

Like many young people of his generation, Hitler became enthralled by May’s popular tales of the American ‘Wild West’ and its ‘Indian wars’. At school, the young Adolf often led his classmates in war games and pranks.³⁵

Hitler’s former teacher, Dr Eduard Huemer, attributed this aggressive youthful behaviour to an excessive addiction to Karl May’s Indian stories.³⁶ As an adult, Hitler himself attributed a drop in his school marks to the time when, as an adolescent, he started to become absorbed with May’s novels.³⁷ After attending a 1912 lecture in Vienna by the novelist, the young Hitler became caught up in the ‘May cult’ and grew to be one of Karl May’s greatest admirers.

Hitler’s fascination with May and his ‘Wild West’ novels never faded, becoming a lifelong addiction.³⁸ During the election campaign of October 1932 (for the forthcoming 6 November national elections), Hitler admitted to still being thrilled by Karl May’s cowboy and Indian stories, with their tales of the ‘Wild West’ and its ‘Indian wars’.³⁹ For inspiration, Hitler read all 70 volumes of May’s works shortly after becoming German chancellor in January 1933.⁴⁰

German Chancellor Hitler kept vellumbound volumes of May’s works on a special shelf in his personal library. A visitor to the Obersalzberg, Hitler’s Bavarian mountain retreat, in 1933, noticed that the majority of books in the Führer’s modest first‐floor room were May’s adventure stories. When German officers, in the spring of 1940, objected to his military plans, Hitler overrode all their objections, observing that ‘They should have read more Karl May!’⁴¹

During one of his famous wartime monologues, he insisted that every German officer should carry one of May’s ‘Indian books’ (Indianerbücher). At the height of the fighting on the Eastern front, in fact, the Führer ordered 300,000 copies of May’s books printed and given to German troops to help defeat the Russians (who, after all, fought like ‘Indians’).⁴²

Thanks to the influence of Karl May, in Hitler’s spatial imaginary, the Nazi ‘Wild East’ had become the American ‘Wild West’, and the ‘Russian [insert slur here]’ had become the ‘savage’ American ‘Red Indians’.

(Emphasis added. Plenty more U.S. sources of inspiration for the Third Reich can be learned in Mr. Kakel’s book.)