BEFORE WE START: Sectionalism has quite a few definitions. I don't know what it means, but I'm willing to do some research and provide you with the best definition.
DEFINE SECTIONALISM: →When you are loyal to someone's region or their section of a country (if they're not "over" an entire country). →"Undue concern with local interests or petty distinctions at the expense of general well-being" -Google
WHY TWO DEFINITIONS? This word could mean a few different things depending on how you use it, so I'm going to leave it up to you to find out which definition you want to use.
The Purpose was to Abolish (Get rid of) Slavery, after the civil war began the "Reconstruction Era" where many people wanted to Reconstruct America after the Civil War, Examples of this was the 13th Amendment (No more Slavery).