What role did religion play in the reform movements that followed the War of 1812?
Religion played a dominant role in the reform movements that followed the War of 1812 (and that, more importantly, followed the Second Great Awakening). The Second Great Awakening called people to take control of their salvation. It, unlike the First Great Awakening, did not hold to Calvinist ideas of predestination. Instead, it held that people could work to deserve salvation.
Because the Second Great Awakening emphasized that people could help themselves, it encouraged them to perfect their societies as well. If people could make themselves better, then why couldn’t they make society better as well? The urge to make society better was the dominant force behind the reforms of the 1830s and beyond. People started to engage in reform efforts that were meant to lift up people who were treated poorly (slaves, the insane, criminals, etc.) and those that were meant to improve society (temperance, public education, etc.). They were driven in many cases by the religious conviction that, in improving their society, they were improving themselves as well.
Thus, the religious fervor that sprang out of the Second Great Awakening was perhaps the dominant force behind the reform movements of the 1830s and beyond.