In February of 1834, Jesus instructed Joseph Smith to raise an army and go to Missouri to rescue Zion from the hands of the Gentiles—by force if necessary. The leaders of the Church unanimously approved this plan, and they named Smith "commander-in-chief of the armies of Israel". Volunteers were recruited over the next few months, and by May a force that eventually included 200 men started on its march across Ohio, Indiana, Illinois, and Missouri.
Keeping the army fed proved a continuous problem, and the men were forced to ration their portions of rotten ham, stale bread, rancid butter, raw pork, cornmeal mush, and maggot-infested bacon and cheese. The average age of the troops was 29, but they ranged from the 79-year-old Samuel Baker to the 16-year-old cousin of the prophet named George A. Smith.
The army of Israel strongly emphasized spirituality. They prayed together daily, and the men were also encouraged to pray privately each morning and night. They knew that Jesus was with them, for they saw his angels leading the way and accompanying them on their march, and so their faith was unwavering.
On June 2, just after crossing the Illinois River at Phillips Ferry, the army came across a great mound of earth with human bones around it, and the remains of what appeared to be three ancient altars. A skeleton was dug out from the ground nearby, and the prophet received a revelation from Jesus that these were the remains of a Lamanite warrior named Zelph who had perished in the final struggle between the Nephites and Lamanites.
By the time the army of Israel entered Missouri, anti-Mormon forces had learned of their approach and prepared for battle, and mobs were ready to attack any Mormons attempting to resettle in Jackson County. Five armed Missourians rode out to where Smith and his men were camped. Amid cursing and boasts about the size or their forces, they swore the Missourians would "utterly destroy the Mormons."
Days later, the prophet received a revelation from Jesus disbanding the army of Israel, and expressing the Savior's dissatisfaction with the members of the Church for their disobedience and selfishness. Smith explained to his troops that the Messiah had promised that Zion would be rescued at some future time, and that Jesus had wanted to test their faith by calling them to march out to Missouri.
Some of the Saints were angry and unsatisfied with this revelation and apostatized. Smith warned them that Jesus would send a devastating plague upon them for complaining unrighteously. Within days, 68 of the men in the camp—including the prophet—had contracted cholera, and the dreaded disease caused vomiting, severe diarrhea, and cramps. Fourteen of them died, one of them a woman traveling with them.
Smith prevailed upon the men to humble themselves before Jesus and promise to keep his commandments and obey the words of his prophet. They did so, and the plague was stopped with not another case of cholera among them. The Missouri Saints hoping to move back to their homes in Independence now looked to settle in the northern part of the state as the prophet and his remaining soldiers headed back to Kirtland.