A candidate from a split party typically doesn’t win the presidency and a contested convention doesn’t create momentum that a candidate needs to oppose the other party
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).
Yes, there are Nile crocodiles, hippo's, Rhinos etc.
A) The South didn't need to conquer the North to win its independence.
The South was just planning on defending itself till the North grew tired, but the North had to conquer the South to be able to reunite the Union and win the war.