When you say "factors," I assume that you mean events. I will identify some events from the 1850s that had a great deal to do with causing sectional hatred.
To me, the most important factor was the Kansas-Nebraska Act. This act reopened the issue of slavery in areas where it had supposedly been settled by the Missouri Compromise. The fighting in Kansas caused a great deal of hatred between the sections. A major example of this is how it destroyed the national political parties and created smaller political parties with support in only one section or the other.
Other factors included, in descending order of importance
- The Dred Scott decision which took away Congress's ability to compromise over the issue of slavery in the territories.
- The Fugitive Slave Act.
- John Brown's attack on Harper's Ferry.
- Preston Brooks' attack on Charles Sumner in Congress.