The battalion marched from Council Bluffs, Iowa, starting on 20 July 1846, arriving on 1 August 1846 at Fort Leavenworth, Kansas. There, the men were outfitted for their trek to Santa Fe. Battalion members drew their arms and other supplies, as well as a clothing allowance of forty-two dollars, at the fort. Since a military uniform was not required, many of the soldiers sent their clothing allowances to their families in the Mormon encampments in Iowa.
The march from Fort Leavenworth was delayed by the sudden illness of Colonel Allen. Capt. Jefferson Hunt was instructed to begin the march to Santa Fe. He soon received word that Colonel Allen was dead. Allen's death caused confusion regarding who should lead the battalion to Santa Fe. Lt. A.J. Smith arrived from Fort Leavenworth claiming the lead, and he was chosen the commanding officer by the vote of battalion officers.
A Dr. Sanderson accompanied the battalion. With antiquated medicines, Sanderson treated the soldiers, who suffered from heat exhaustion, lack of food, and forced long-distance marches. Twenty men died later as a result of their service in the battalion.