They wanted the holy land back
The Black Sea was the waterway most controlled by the Byzantine Empire during its height and most of its existence. Constantinople which is nowadays know as Istanbul was the capital city of the empire and it was located in the Bosphorus strait, which is the connecting link between Mediterranean Sea and the Black sea.
That geographical area was a strategic point for commercial routes between Europe and Asia, and it was also military disputed due to be considered the entrance to Europe for eastern invaders.
The draft laws allowed substitutes , meaning the rich could get out of serving in the army. this naturally made those who could't afford a substitute to be angered . ( typically, substitutes could be purchased for $300 -- and $300 in 1863 was a bout the equivalent to almost $6,000 in modern terms. <span />
C. I really don't have an explanation for this, but I know this from a BrainPOP video. Hope I helped! ☺
