I was fortunate enough to get my hands on an advance copy of Dr. Megan Kate Nelson's The Three-Cornered War: The Union, the Confederacy, and Native Peoples in the Fight for the West which comes out next month. Only half way through so far, but it is excellent. It presents a well written, gripping narrative about the conflict in the region of New Mexico/Arizona. It does a really great job weaving together the stories of the soldiers on both sides, as well as the civilians caught in the middle, and the indigenous peoples over whose lands the Union and Confederate forces were fighting for control of. It doesn't come out until next month, but I would definitely recommend it!