The issues that caused sectionalism to develop were:

Sectionalism was caused by multiple issues at that time. It occurred because of slavery, slave power conspiracy, economic differences and cultural differences. The main cause of sectionalism was slavery because how Northerners don’t like how Southerners don’t see the immorality of it. 

answer: nope

explanation: because theirs barely anyone on here to you. but let me see the question. maybe i can , if i know the answer!

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.