Charles Grandison Finney followed these political developments from Oberlin College, where he served as president in the 1840s. Skeptical that electoral politics could transform society, he continued to view individual conversions as the wellspring of change. As the nation expanded westward, he trained ministers to travel the frontier converting American Indians to Christianity and reminding pioneering families of their religious obligations. Amy Post took a more militant stand, rejecting any participation in a government that accepted slavery and fomented war. She disagreed with Frederick Douglass’s decision to support the Liberty Party, but he argued that moral persuasion alone would never convince planters to end slavery.

The efforts of the tens of thousands of Northerners inspired by religious and reform movements between 1820 and 1850 had a greater impact because of the growth of cities and improvements in transportation and communication. It was far easier by the 1830s for evangelicals, Quakers, Mormons, transcendentalists, utopian communalists, and other activists to spread their ideas through sermons, lectures, newspapers, pamphlets, and conventions.

Urban development was driven by the migration of native-born Americans from rural areas and small towns as well as the increase in immigration from Ireland, Germany, and other European nations. While the panic of 1837 fueled an economic crisis that lasted several years, it also inspired many Americans to organize against poverty, intemperance, prostitution, and other urban problems. At the same time, the concentration of workers, immigrants, and free blacks in cities allowed them to unite and claim rights for themselves. For workers, the need to organize was heightened by the growth of factories and factory towns even as the increasing diversity of the labor force aroused tensions among distinct racial and ethnic groups. Thus numerous attacks occurred against free blacks who competed for jobs with immigrants and poor whites even as the antislavery movement expanded across the North.

Of the numerous reform movements that emerged in this period, abolitionism carried the most powerful national implications by 1850. The addition of vast new territories at the end of the Mexican-American War in 1848 ensured that those concerns would become even more pressing in the decade ahead.