What is the importance of the battle between the Merrimack and the monitor

The battle between the Monitor and the Merrimac (This was the ship's name when it was a US Navy ship. The CSA renamed it the Virginia) was the most famous naval encounter of the American Civil War. It is important because it showed that the era of wooden ships was coming to an end.

she will pay the extra amount

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.