There should be understanding at the outset that the Mormon Battalion was a part of the volunteer soldiery of the Mexican War. At the time there was a regular army of very small proportions, and that was being held for the descent upon the City of Mexico, via Vera Cruz, under General Scott. General Taylor had volunteers for the greater part of his northern army in Mexico. Doniphan in his expedition into Chihuahua mainly had Missouri volunteers. In California was looming a very serious situation. Only sailors were available to help American settlers in seizing and holding the coast against a very active and exceptionally well-provided and intelligent Mexican, or Spanish-speaking, opposition. Fremont and his "surveying party" hardly had improved the situation in bringing dissension into the American armed forces. General Kearny had been dispatched with all speed from Fort Leavenworth westward, with a small force of dragoons, later narrowly escaping disaster as he approached San Diego. There was necessity for a supporting party for Kearny and for poor vision of troops to enforce an American peace in California. To fill this breach, resort was had to the harassed and homeless Saints. The route was taken along the Santa Fe trail, which then, in 1846, was in use mainly by buffalo hunters and western trading and trapping parties. It was long before the western migration of farm seekers, and the lure of gold yet was distant. There were unsatisfactory conditions of administration and travel, as narrated by historians of the command, mainly enlisted men, naturally with the viewpoint of the private soldier. But it happens that the details agree, in general, and indicate that the trip throughout was one of hardship and of denial. There came the loss of a respected commander and the temporary accession of an impolitic leader. Especially there was complaint over the mistaken zeal of an army surgeon, who insisted upon the administration of calomel and who denied the men resort to their own simple remedies, reinforced by expression of what must have been a very sustaining sort of faith. A more popular, though strict, commander was found in Santa Fe, whence the Battalion was pushed forward again within five days, following Kearny to the Coast. The Rockies were passed through a trackless wilderness, yet on better lines than had been found by Kearny's horsemen. Arizona, as now known, was entered not far from the present city of Douglas. There were fights with wild bulls in the San Pedro valley, there was a bloodless victory in the taking of the ancient pueblo of Tucson, there was travail in the passage of the desert to the Gila and a brief respite in the plenty of the Pima villages before the weary way was taken down the Gila to the Colorado and thence across the sands of the Colorado desert, in California, to the shores of the western ocean.