Answer:
They believed that those things represent their historical heritage.
Step-by-step explanation:
Confederates symbols and monuments were considered very controversial in United States. These symbols represent a group who in the past fought to keep African American as Slaves.
Due to this historical significance, confederate symbols and monuments are generally looked with disdain by the majority of United States citizens (especially the ones who live on northern states). They wanted those symbols/monuments to be completely destroyed.
That being said, There were some supporters of these symbols & monuments. They argued that these monument represent historical heritage of the Southern States and part of the journey that United States had to experience to come to this point.