The River War was published in two editions, one in 1899 and the second in 1902. There are two volumes to the 1899 edition, each a little over 500 pages long. The 1902 edition is highly abridged and contains only about 230 pages. Your quote comes from the 1899 edition, not the 1903 edition. The 1899 edition, of which only about 1,000 copies were published, is far richer, containing many excellent maps illustrations, none of which appears in the Kindle edition. Until recently, it's been very hard to find the first edition, even on line. However, that's different now and any one of us can download an entirely readable, unabridged PDF copy of each volume at:
https://archive.org/search.php?query=The%20River%20War
I've done it and am now into the second volume. I strongly encourage all FReepers to do it. It's an excellent book.