I'm reading a number of books right now including Frontiersman in Blue: The U.S. Army and the Indian 1848-1865 by Robert Utley. Good book, but what I have found most interesting is the similarities of the U.S. Cav and their outposts and missions during this time period to the mission of the Army and USMC in Afghanistan and Iraq. Of considerable interest was the description of the Cav mission (page 110) where soldiers did not march west as conquerers, but to serve as policemen. Obviously the book goes on to describe much more then I am willing to go into here.