Manly Wade Wellman 
The Timeless Tomorrow [EPUB ebook] 

They’re a group of rebels in the far future trying to save mankind. Join them as they travel through both space and time tying to defeat a fascist government that wants to control time itself. The Rebels are seeking a better future, but will they find it or will they create a future that’s even worse than what they’re trying to prevent? An exciting ride through time! You won’t soon forget the stunning conclusion.