You can do it either way but I strongly recommend starting with the first book since there is some overlap with prior books in the series. I get the impression that River of Souls was not among the most popular in the series because it was very short.
I also had a lot of trouble buying the angle that any whites of that time would be sympathetic to slaves associated with a murder and give them a fair chance to explain themselves - some modern mindset creeping into the 18th century, but it is still good though.
I just finished "The Wolf's Hour" a sort of James Bond werewolf story set in WWII. Not my favorite of McCammon's books. I find any historical fiction set in WWII to be hard to read. It basically means the author only has to have about a middle school level understanding of the historical context (Germans = bad Americans/Brits = good) and is looking for a larger audience of readers with an interest in that war. There is an entire genre of bad historical fiction set in WWII. Much harder to research and write the Corbett books set in the early 1700's. Wolf's Hour has its moments but reads more like an author searching for mainstream subjects to gain a larger audience.
