Due to the rise of the Nazis in Germany, Eichengrün was unable to object when Hoffman first made the claim that "he" (Hoffman) invented aspirin, in the footnote of a 1934 German Encyclopedia. Hoffman's claim was once widely accepted, but many historians now consider it to be discredited. Eichengrün first claimed to have invented aspirin in a 1944 letter from Theresienstadt concentration camp, addressed to IG Farben (of which Bayer was a part), where he cited his many contributions to the company (which was highly influential in the concentration camps), including the invention of aspirin, as reasons for why he should be released.