Plz help me on history

What event caused south carolina to secede from union in 1860

How did the battle of okinawa affect president truman’s decision to use the atomic bomb against japan? it showed that japan was close to surrendering. it showed that the us could not win the war without it. it showed that japan was willing to fight to the end. it showed the us could easily defeat japan.

What religion influenced the first persian empire as established by cuyrus the great?