The collection culture in America was unique worldwide. Since the country had a short history, they did not have anything like antiques or artifacts. Thus, their collection culture was more applicable to their modern lives.
Comic collection was one very important branch in the American collectors' world. Everyone knew that the otaku (nerd) culture was well-developed in Japan, but the American otaku culture was very advanced as well.
Moreover, not only nerds collected comic books in America. A few generations of Americans had grown up on comic books, and it was part of their culture.
For example, in the famous American drama series 'Big Bang', there were many comic books, garage kits, and peripheral products shown on screen, as the four male leads in the drama were comic lovers.
