Joseph Smith's Role in Early Mormonism and the Nauvoo Period

How Smith transformed a small religious movement into a political and social force, then fractured it through secrecy and power consolidation.

By Garret Merkley · Explainer · Jun 11, 2026

Branched from Polygamy in Nauvoo: The Secret Practice That Fractured the Community

Quick take

Smith founded Mormonism in 1830 and guided it through persecution, migration, and rapid growth, but centralized authority in himself.
In Nauvoo (1839–1846), he became mayor, militia commander, and religious leader—accumulating power that alarmed both followers and outsiders.
His introduction of plural marriage in secret, combined with claims of continuous revelation, created internal conflict and contributed to his assassination in 1844.

Joseph Smith was the founder and central authority of the Church of Jesus Christ of Latter-day Saints, from its formal organization in 1830 until his death in 1844. He claimed to receive direct revelation from God, which he recorded and taught as scripture. His role was not merely spiritual—he was a translator (of what he called the Book of Mormon), a prophet, a political leader, and eventually the architect of a theocratic community. Understanding Smith's position during the Nauvoo period (1839–1846) requires seeing how his religious claims, personal ambitions, and organizational control intersected to reshape his movement and ultimately trigger its collapse.

Building Authority Through Revelation

Smith's power rested on a unique claim: that God spoke to him directly and continuously. In 1830, he published the Book of Mormon, which he said he had translated from golden plates shown to him by an angel. This text became the foundational scripture of his church and established Smith as a prophet—someone with unmediated access to divine will. Unlike Protestant ministers who interpreted existing scripture, Smith could declare new doctrine at any time simply by announcing a revelation. This mechanism allowed him to adapt the religion to circumstances, introduce new practices, and maintain control over theological direction. Early followers accepted his revelations as binding because they believed his prophetic claim was genuine.

As the movement grew, Smith formalized this authority through church structure. He appointed himself as president of the church with two counselors, created a Quorum of Twelve Apostles, and established a hierarchy of priesthood ranks. Each level reported upward; each doctrine flowed downward from Smith. This vertical organization meant that dissent from Smith's teachings was treated as rebellion against God's chosen vessel. When followers questioned his decisions—whether about finances, doctrine, or personal behavior—they risked excommunication and social exile from a tight-knit community that often depended on the church for survival.

The Nauvoo Experiment: Religious Power Meets Temporal Rule

After persecution in Ohio, Missouri, and Illinois forced the church to relocate repeatedly, Smith and his followers settled in Nauvoo, Illinois, in 1839. The state granted them a charter that allowed the church to incorporate as a city with its own militia (the Nauvoo Legion) and local government. Smith became mayor, commander-in-chief of the militia, and the religious leader—a consolidation of religious, military, and civil authority unprecedented in American religious history. He appointed his close allies to key positions, ensuring that every lever of power in Nauvoo ultimately answered to him. By the early 1840s, Nauvoo was the largest city in Illinois by some measures, and Smith controlled it absolutely.

This concentration of power enabled Smith to pursue practices that would have been impossible in a more dispersed or accountable setting. He used the Nauvoo Legion to enforce church discipline, protect church property, and intimidate critics. He established an inner council called the Council of Fifty, which discussed not only religious matters but also political governance and even Smith's ambitions to run for U.S. president. The line between church and state had collapsed entirely. For loyal members, Nauvoo felt like a kingdom of God on earth. For outsiders and dissenters, it looked like a dangerous theocracy.

Plural Marriage and the Fracture Within

Smith's most destabilizing doctrine—plural marriage, or polygamy—was introduced secretly in Nauvoo and revealed to only a small inner circle. Smith claimed to have received a revelation in 1831 authorizing men to take multiple wives, but he did not announce it publicly until 1852, eight years after his death. Instead, he married at least 30 women between 1841 and 1844, often without the knowledge of his legal wife, Emma, and sometimes without the knowledge of the women's families. Some of these women were teenagers; some were already married to other men (a practice called polyandry). Smith justified the practice through theological arguments about exaltation and sealing, but he introduced it through personal persuasion, coercion, and manipulation rather than open doctrinal teaching.

The secret practice of plural marriage created a hidden power structure within Nauvoo. Women who entered into these arrangements with Smith gained status and access to him; their families gained prominence. But the secrecy also bred resentment. When Emma discovered the practice, she was devastated and opposed it fiercely. Other church members who learned of it felt betrayed—they had believed Smith's public denials that the church practiced polygamy. Some began to question whether Smith's revelations were genuinely from God or whether he was using his prophetic authority to justify personal desires. This doubt, more than any external persecution, began to splinter the movement from within.

Why Smith's Nauvoo Period Matters

Smith's role during the Nauvoo period reveals the dangers of unchecked religious authority combined with political power. He demonstrated how a charismatic leader with a claim to divine revelation can build a devoted following and then use that following to accumulate resources, land, and control. His introduction of secret doctrines—particularly plural marriage—showed how such authority can be weaponized to justify practices that contradict public teachings and exploit vulnerable people. When his followers began to lose faith in his integrity, they did not simply leave the church; many felt betrayed and angry, and some sought to stop him. His assassination in 1844 by a mob in Carthage, Illinois, was partly a response to his overreach and the fear he inspired in both his enemies and his own increasingly disillusioned followers. The Nauvoo period is a case study in how religious movements can transform from persecuted minorities into authoritarian structures, and how the loss of transparency and accountability can destroy even a movement with deep conviction and loyalty.

Key Dates in Smith's Nauvoo Period

1839: Smith and followers settle in Nauvoo, Illinois
1840: Nauvoo incorporated with Smith as mayor and militia commander
1841–1844: Smith secretly marries at least 30 women
1844: Smith announces candidacy for U.S. president; internal opposition intensifies
June 27, 1844: Smith and his brother Hyrum are killed in Carthage jail

Did Smith's followers know about his plural marriages while he was alive?

Most did not. Smith kept his marriages secret from the general church membership and from his legal wife, Emma. Only a small inner circle of trusted associates knew. When rumors circulated, Smith publicly denied practicing polygamy. This secrecy was deliberate and central to his control—it created an inner circle of initiates who felt special knowledge and loyalty, while keeping the broader membership in the dark.

Why did Smith combine religious and political power in Nauvoo?

Smith believed that God's kingdom should govern all aspects of life, not just spiritual belief. He saw no separation between church and state as legitimate. The Nauvoo charter gave him the legal opportunity to do this, and his theological worldview justified it. The result was a theocracy in which religious obedience and civic obedience were inseparable.

Did Smith's death end polygamy in the Mormon church?

No. After Smith's death, the church split into several factions. The main body, led by Brigham Young, continued and openly practiced plural marriage after migrating to Utah in 1847. The practice persisted until the 1890s, when the church officially discontinued it under pressure from the U.S. government. Other branches, like the Reorganized Church of Jesus Christ of Latter Day Saints (now the Community of Christ), rejected polygamy and distanced themselves from Smith's Nauvoo-era practices.

How did ordinary church members react to discovering Smith's plural marriages?

Reactions varied. Some felt betrayed and left the church. Others rationalized it as a divine test of faith. Some, particularly women in the inner circle, accepted it as God's will. The discovery of the practice was a major factor in the internal opposition to Smith in 1844, with some members printing a newspaper called the Nauvoo Expositor to publicly expose what they saw as Smith's hypocrisy and abuse of power. Smith's response—using the Nauvoo Legion to destroy the printing press—further inflamed tensions.

Was Smith's assassination a result of his religious teachings or his political actions?

Both. Non-Mormons in Illinois feared his political ambitions and the power of the Nauvoo Legion. Dissident Mormons were angry about his secret marriages and his use of religious authority to silence critics. The mob that killed him included both outsiders and former church members. It was the collision of all these tensions—religious, political, and personal—that led to his death.

Sources

Bushman, Richard L. Joseph Smith: Rough Stone Rolling (2005) — comprehensive biography covering Smith's life through Nauvoo.
Compton, Todd. In Sacred Loneliness: The Plural Wives of Joseph Smith (1997) — detailed documentation of Smith's marriages and the women involved.
Givens, Terryl L. The Viper on the Hearth: Mormons, Myths, and the Construction of Heresy (1997) — analysis of how non-Mormons perceived Smith and Nauvoo.
Historical records from the Church History Library and Nauvoo Restoration, Inc.