The Assassination of Joseph Smith: A Turning Point in Latter-day Saint History

How the 1844 murder of the LDS founder in Illinois fractured the church and forced its westward migration.

By Garret Merkley · Explainer · Jun 7, 2026

Branched from The Nauvoo Exodus: Why Latter-day Saints Migrated West

Quick take

Joseph Smith, founder of the Latter-day Saint movement, was killed by a mob in Carthage, Illinois on June 27, 1844, while jailed on charges related to polygamy and press suppression.
His death removed the central authority figure and created a succession crisis that split the church into multiple factions with competing claims to legitimacy.
The assassination accelerated the church's departure from Illinois and became a rallying narrative for the Utah-bound migration under Brigham Young's leadership.

Joseph Smith, the founder and prophet of the Church of Jesus Christ of Latter-day Saints, was shot and killed on June 27, 1844, by a mob while imprisoned in Carthage, Illinois. He was 38 years old. The assassination did not simply end a life—it shattered the institutional structure of the LDS Church, which had been built almost entirely around Smith's personal authority and claimed prophetic status. His death created an immediate succession crisis, triggered the fragmentation of the movement into competing branches, and fundamentally changed the trajectory of Latter-day Saint history by forcing the church to reimagine itself without its founder.

The Crisis Leading to Smith's Arrest

By 1844, Joseph Smith had accumulated enemies both inside and outside the Latter-day Saint community. Within the church, Smith's practice of polygamy—which he had kept secret from most members and church leadership—became a source of profound discord when it was discovered. Emma Smith, his wife, was devastated and opposed the practice vehemently. Some prominent church members, including William Law, broke with Smith over the issue and began publishing the Nauvoo Expositor, a newspaper that accused Smith of tyranny, fraud, and sexual misconduct.

Outside the church, non-Mormon residents of Hancock County, Illinois had grown increasingly hostile to the LDS presence. The Latter-day Saints had become a significant voting bloc and economic force in the region, and their insularity and rapid growth alarmed the broader population. Local authorities issued a warrant for Smith's arrest on charges of treason against the state of Illinois—a charge stemming from his use of the church's militia, the Nauvoo Legion, and his suppression of the Expositor press. Smith initially fled to Iowa but returned to Carthage to face trial, believing he could clear his name.

The Mob and the Murder

While Smith was held in Carthage Jail awaiting trial, a mob of approximately 100 to 200 men, some with blackened faces, stormed the building on the afternoon of June 27, 1844. The mob's composition is debated by historians—some were likely anti-Mormon vigilantes, while others may have been disaffected church members. The county militia, which was supposed to guard Smith, either dispersed or stood aside. Smith and his brother Hyrum, who was also imprisoned, were shot multiple times. Joseph Smith was shot at least four times and died almost immediately; Hyrum died first, shot through a window before the mob entered the cell block.

The mob's action was not prosecuted effectively. The perpetrators were either never identified or were acquitted when brought to trial. The failure of the legal system to hold anyone accountable deepened the Latter-day Saints' sense of persecution and their conviction that they could not find justice or safety in Illinois.

Succession Crisis and Fragmentation

Smith had not clearly designated a successor, and the church had no established mechanism for choosing a new prophet. Within weeks, multiple claimants emerged. Brigham Young, the senior member of the Quorum of the Twelve Apostles, asserted that the apostolic quorum should lead the church collectively, with Young as its president. Emma Smith, supported by some church members, argued that the presidency should pass to Joseph Smith III, her son with Joseph, who was only 11 years old at the time. Other groups rallied behind different figures, including James J. Strang, who claimed to have received a letter from Joseph Smith naming him as successor, and Sidney Rigdon, who had been Smith's counselor.

Brigham Young's faction, which included most of the apostles and the bulk of the church's membership in Nauvoo, ultimately prevailed. Young's organizational skill and his control of the church's infrastructure allowed him to consolidate power. However, the succession dispute resulted in permanent schisms. Emma Smith and her followers eventually organized the Reorganized Church of Jesus Christ of Latter Day Saints (now the Community of Christ), which rejected polygamy and maintained that Joseph Smith III was the rightful leader. Strang's followers migrated to Wisconsin and Michigan. These divisions meant that the unified movement Smith had built fractured into multiple churches, each claiming to represent the true continuation of his work.

Why the Assassination Mattered and When It Became a Turning Point

Smith's death was the watershed moment that made the Latter-day Saints' departure from Illinois inevitable. Before the assassination, some church members hoped to remain in Nauvoo and establish a permanent settlement. After Smith's murder and the evident failure of local authorities to protect him or punish his killers, the church's leadership concluded that coexistence with non-Mormon neighbors was impossible. The assassination became a founding trauma for the LDS Church—a narrative of persecution that justified both the exodus westward and the church's subsequent insularity and self-reliance.

The assassination also accelerated the succession of power to Brigham Young and the apostolic leadership model that would define the LDS Church for the next century and a half. Had Smith lived, the church might have developed differently—possibly remaining in the Midwest, possibly maintaining a more decentralized structure, possibly never adopting Utah as its headquarters. Smith's death created a vacuum that Young filled with remarkable efficiency, and in doing so, Young set the church on a path toward the Great Plains and the Great Salt Lake Valley.

Key Context: Nauvoo Before the Assassination

By 1844, Nauvoo, Illinois was the largest city in the state by some measures, with approximately 12,000 LDS residents.
The church had established its own militia (the Nauvoo Legion), courts, and economic institutions, creating a near-theocratic community.
Joseph Smith had become mayor of Nauvoo and exercised both religious and civil authority, which alarmed non-Mormon neighbors.
Smith's practice of polygamy was still largely unknown to the general membership and was a source of internal conflict among church leadership.

Was Joseph Smith's assassination a premeditated conspiracy, or a spontaneous mob action?

Historians debate the degree of organization behind the mob. Some evidence suggests anti-Mormon vigilantes had planned to remove Smith as a threat, while other accounts describe a more spontaneous gathering of angry residents. The mob's composition—partly local anti-Mormon settlers, partly disaffected church members—suggests both planned and opportunistic elements. No definitive conspiracy was ever proven in court.

Could Joseph Smith have survived if the militia had actually protected him?

Almost certainly. The militia was supposed to guard the jail but either dispersed before the mob arrived or actively cooperated with the attackers. Had the guards remained loyal and resisted, the mob would likely have retreated. The failure of law enforcement was a critical factor in Smith's death.

Why did the Latter-day Saints blame all of Illinois for Smith's death, rather than just the local mob?

The church leadership interpreted the mob action as reflecting the broader hostility of Illinois society toward the LDS community. When local authorities failed to prosecute the perpetrators, it seemed to confirm that the state would not protect Mormon rights. This perception—whether fully accurate or not—became the basis for the decision to leave Illinois entirely.

Did Brigham Young have anything to do with Smith's death?

No credible historical evidence supports this claim. Young was in Boston on a church mission when Smith was killed. Young's consolidation of power after Smith's death was rapid and effective, but it resulted from his organizational skill and the support of the apostolic quorum, not from any involvement in Smith's assassination.

How did the different LDS factions view Smith's death?

All factions saw Smith's death as a tragedy and a persecution, but they interpreted its meaning differently. Young's faction used it to justify the westward migration and the need for a strong, unified leadership. Emma Smith's faction saw it as a reason to reject some of Joseph's later teachings (particularly polygamy) and return to earlier principles. Strang's followers saw it as validation of their claim that Strang was Smith's true successor.

Sources

Bushman, Richard Lyman. Joseph Smith: Rough Stone Rolling. Knopf, 2005. — Standard scholarly biography covering Smith's life and death.
Compton, Todd. In Sacred Loneliness: The Plural Wives of Joseph Smith. Signature Books, 1997. — Documents Smith's polygamy and its role in the conflict leading to his death.
Givens, Terryl L. The Viper on the Hearth: Mormons, Myths, and the Construction of Heresy. Oxford University Press, 1997. — Analyzes anti-Mormon sentiment and violence in 19th-century America.