The Muslim community spread through the Middle East through conquest, and the resulting growth of the Muslim state provided the ground in which the recently revealed faith could take root and flourish. The military conquest was inspired by religion, but it was also motivated by greed and politics
Ending slavery immediately would have had a devastating effect on the economy which had become dependent on cheap slave labor. It would have also motivated the South to secede. The slaves would have also been left without an immediate source of sustenance.
