What was the major issue between northern and southern states after 1820?

slavery

Explanation:

The issue of slavery caused tension between the North and the South. In the North, the antislavery movement had slowly been gaining strength since the 1830s. Abolitionists believed that slavery was unjust and should be abolished immediately. Many Northerners who opposed slavery took a less extreme position.

its b they wanted to be able to expand their trade..

the puritans were a group of people who grew discontent in the church of england the common unity strengthened the community.