This book is the first in the Riverworld series by Farmer. It reminds me very much of Heinlein at his most cantankerous and misanthropic. The story is that all the human beings that have ever lived wake up at the same time on the banks of a river millions of miles long.
The protagonist is a real person - Richard Burton. No not that one. He was a 19th century explorer and translator of The Thousand and One Nights. Another character in the novel is the Alice that inspired Alice in Wonderland and another character is Herman Goering. I liked that aspect of the book - the fantastic elements. The human interaction has some of that weird American (especially Heinlein) science fiction view of people that has so little truth to it. There is quite a bit of warring in what essentially is an intrinsically egalitarian society with nothing to war over. It was also written in 1971 and drugs are seen as both potentially dangerous, but also potentially consciousness expanding.
Its quite interesting and inventive. It's not amazing. I think the whole Riverworld series is not seen as in the most important tier of Science Fiction, but on the next level down. That feels about right to me.