Actually, the appearance of Cap 1 caused a lot of ruckus. At that point, many Americans hadn’t decided if this Hitler guy was really bad or not, with some actually liking the guy( and fast forward to today: the more things change, the more they stay the same). So when this book was published, there was a backlash from a certain segment of the population. So much so that the mayor of New York had to provide police protection to Simon and Kirby. It’s easy to look back now and know what a monster Hitler was, but at the time, this was groundbreaking stuff