Comic Book Ages: The Golden Age

Nothing I like better than a good, old-fashioned, fanboy geek discussion over where the various comic book "ages" begin and end.

For my criteria:

1. Must point to a single comic book.
2. Impact must have been immediate.
3. Comic books before this book was published and after it must largely be different.

Pretty simple, right?

Well, here's my selection for the book that spawned the Golden Age of Comics:



No controversy here.

Before Superman, comic books were chiefly reprints of comic strips, with some original tales of established comic strip characters. Afterword, comics were original material, and the superhero genre was born.