What is important about the meeting between the confederate officers and Major
Anderson?

It lead to a truce between them

Explanation:

Meeting with Major Anderson, he said, "You have defended your flag nobly, Sir. You have done all that it is possible to do, and General Beauregard wants to stop this fight. On what terms, Major Anderson, will you evacuate this fort?" Anderson was encouraged that Wigfall had said "evacuate," not "surrender." He was low on ammunition, fires were burning out of control, and his men were hungry and exhausted. Satisfied that they had defended their post with honor, enduring over 3,000 Confederate rounds without losing a man, Anderson agreed to a truce at 2:00 p.m