This note contains spoilers for the book.

It's a collection, dating much earlier than the copyright given. This ACE edition doesn't give details on previous publication, so you'll have to use the bibliography link to find them in the ISFDB.

If you're not up on the history of SF, I should mention that Piper is one of the tragic figures -- dead of depression-induced suicide at the top of his form, because he thought his career was a failure.

Piper was an early player at "future history". His future history covered many rises and falls of the Terran Federation (and related polities), over rather a long time. This book collects the stories with information about this. As would happen in the real world, the stories aren't fully compatible -- this small a sampling of stories from such a big period will never be completely descriptive or even consistent.