Who knew my childhood hobby would turn so devilishly rabid? Volume1: the US? Wow. Impressive documentation, pictures and manual on how to decipher the latest philatelist secrets in past and present releases. Mark that manual, your going to need it! Bought it used, seemed pricey but after reviewing the depth and detail of the latest catalog- I get it, and it was worth it. I doubt I'll need an update for several years and of course, historically, it will remain accurate. Must have for the serious collector or inquisitive amateur.