Please answer this ASAP! i really need help.

1 What were the main issues leading to the secession of Southern states from the Union?
2 Why did the presidential election of 1860 bring the United States closer to civil war?
3 Describe Sam Houston’s role in the events leading to Texas secession.
4 How might the supporters of secession have reacted if Houston had accepted Lincoln’s offer and tried to remain in office?