Which of these was president Lincoln’s central goal during civil war?

•to end slavery in all U. S states
•to preserve the Union
•to keep the U. S economy for collapsing
•to punish the southern states for seceding

basic principles: federalism, separation of powers, checks and balances, judicial review, representative democracy, limited government, rule of law, individual rights and responsibilities, consent of the governed, majority rule, popular sovereignty, equal protection.