- 
  
  The first American Intervention.
- 
  
  Emphasized the evil of slavery. The North becomes increasingly abolitionists. The south grows more defensive of slavery.
- 
  
  Popular Sovereignty will determine slavery issues in any state. Slavery can exist anywhere.
- 
  
  Supreme court rules that Missouri Compromise is unconstitutional. Congress has no power to regulate slavery. Slaves are not citizens thery are property and have no rights.
- 
  
  Radical Abolitionist John Brown attacks federal armory in attempt to start a slave revolt.