Two softcover booklets, first 43 pages, second covers 265-300 pages. University of New Mexico, 1927/28. In very good condition, cover edges are creased, pages are toning. Reprints from The New Mexico Historical Review, Vol. II, Nos. 2-3, April, July, 1927, and Vol. III, No. 3, July 1928. History, covering three decades, of the military mission to protect travel, and commerce, along the Santa Fe Trail.