"Mormon Battalion"
During the time (1846) the Mormons camped at the "Grand Encampment," the government was at war with Mexico (The Mexican War). The Mexican military was led by Antonio López de Santa Anna, who had been victorious at the Alamo. The US military, led by General Zachary Taylor did not want to have a second defeat.
Meanwhile back in Iowa, Brigham Young had petitioned the government for help in locating a place for his people to stay for the winter. In exchange, the Mormons could deliver mail, improve conditions of the passageways to the west, and other services needed so that they could sustain themselves.
The response was a bit of a surprise. The government had worked out a deal with the Indians across the Missouri to allow the Mormons to stay on their land for up to two years but the U.S. government needed a volunteer battalion of 500 soldiers to help fight the Mexican war.
Around July 16th, 1846, Colonel Stephen W. Kearny* send Capt. James Allen* met the Mormons at the Grand Encampment to enlist the battalion. After having received no help from the government prior, there was little incentive for any members to comply, especially having to leave family and community after having made it this far.
It was Brigham Young that realized the value of wages to be earned and the good faith it would create. At first, he asked for volunteers. When only a handful came forward, Brigham spoke with the Captain to ensure that the men would not have to fight in the war but could perform other duties. With a great deal of encouragement, he was finally able to gather enough volunteers to fill the first 4 of the 5 companies needed. Seeing there was still reluctance, Brigham gave an ultimatum of three choices; (1) join the battalion, (2) return to Nauvoo and bring remaining members waiting for assistance, or (3) blaze a trail to the west. In all cases, they would not be allowed to remain with their families. The fifth of five flanks of 100 started to form. At 489 soldiers, 12 teenage boys (aids to officers) from as many as 51 children, and 20 women (laundresses enlisted to perform laundry duties, and meal duties as necessary), the battalion was ready.
On July 21 and 22nd, 1846, the Mormon Battalion set off to march to San Diego, not walk. An additional 40 to 60 family members joined the march. In the hot summer months, the battalion marched 2,030 miles from Kanesville, to Fort Leavenworth, Kansas, then to Pueblo, Colorado, Santa Fe, New Mexico, then on to San Diego. This was the longest infantry march in United States military history. By the time they arrived, the war was already over. Still, the men were enlisted for one year, and stayed until they were discharged.
By the time the battalion was discharged, some of their families had left the Grand Encampment area, and either moved to Winter Quarters across the river or had continued on to the Salt Lake Valley area with other members of the community. Some of the soldiers traveled straight to Salt Lake Valley, and then some of them traveled back to this area to help bring other family members to Salt Lake Valley, making a trip total of around 5,000 miles. This monumental task is difficult to imagine even today. Consider what it would be like doing this without our modern conveniences, and through "Indian Country."
