I gave up something like ¼ in.
There were more than ten pages of the protagonist listening to a speech of Sam Houston. If i wanted to know about Sam Houston, i would read a Sam Houston biography.


(More general rant: The super-famous author & not so famous author combo is always suspect. Often the super-famous author had an idea. Because they are super-famous everybody thinks it must be a good idea. Then the super-famous author can’t be bothered to actually write the book, and hands it off to some other author.
That whole scenario can work, but it is more likely to end in a work that is not that good. Seems to be the case here.)

eta: I guess it was significantly less than ¼ that i read. It just felt like that because the pacing was so slow.