Starts very slow. Tenderfoot comes to Texas. Kills a deer and a bear. Gets lost. Kills an Indian. Gets captured and then adopted by a bereaved squaw. All told in a super laid-back style, like it was normal.
It picks-up in the middle, with the Mier Expedition. One of several/many clashes between Texas and Mexico. Hundreds of Texans and allies were held in Mexico for well over a year, in unhappy conditions. Some escaped. Santa Anna ordered all the escapees to be executed, but compromised for decimation, a 1 in 10 lottery: 17 black beans were put in a pot of white beans, and the men who drew black beans were executed. Much myth-making here. Although the book was written to sell, as entertainment, this passage is apparently as historical as we can expect, seen through the memory of an old man.
Along the way BigFoot insults almost everybody, in words we do not use today. He made deals with some indians but if they broke the pact he punished them with insults and bullets. Twice he goes off on "Negros" (not his word). Then on and on about greasers (Mexicans); I know that long imprisonment does not make friends but he really gets into his subject. Later he goes back East and doesn't like everybody there (and soon returns to Texas), but not in such detail as Indians, Negros, and Mexicans.
Still in all, one angle of the complexities of Texas history, and worth reading for background flavor.