Yes and no. People misunderstand what this mean. His antisemitism wasn't influenced by America, so

>Did he learn how to treat Jews based on the way Americans treated blacks

no.

But when crafting racial laws, specifically those that defined who was or wasn't Jewish as far as Nazis were concerned, Nazis took inspiration of the "one drop rules" in some US laws.

So not in how to treat people, but yes in how to craft laws to discriminate against them.