"After many pages, I had to ask myself…what about the War? It is a topic almost completely missing from the pages of his book. Was he trying to obscure the fact that he did not serve when so many other young men were in the military? Was the War really such a minor topic to those in the Far West?"It's not terribly surprising that Twain doesn't address the war in the book. The motivations of writers in ignoring or pushing far into the background the great events and cataclysms of contemporaneous history have often been questioned. Jane Austen has been frequently criticized for depicting a middle class life in the country that hints little at the momentous political and social upheaval going on just across the Channel in Revolutionary and Napoleonic France and Europe.
Our Jane's question of how interested in the Civil War (after all, thousands fled West to escape its horrors) the people of Far West were is a good one and it's a subject that's being explored in increasing depth. Though still only scratching the surface, a number of recent books and articles have examined how residents of the Pacific Northwest, Montana, and California reacted to the secession and war years.
Most recently, I read a fascinating article edited by Cary C. Collins and published in the Summer 2015 (Volume 29, Number 2) issue of Columbia: The Magazine of Northwest History (the quarterly journal of the Washington State Historical Society) titled "A Most Uncivil Civil War – Registering Walla Walla for the Draft in 1864." Drawing heavily from Eells's own accounts, the article vividly describes the often harrowing experiences of Edwin Eells as a conscription officer in Washington Territory. It provides abundant evidence of just how much the war, national politics, and the draft occupied the minds and actions of those Americans living in places far removed from the actual fighting. I would highly recommend the article to anyone interested in the subject of the war in Far West. A recent book The Civil War and the West: The Frontier Transformed also offers a lengthy and helpful bibliographical essay, pieces of which one can view at the link provided.