Why are the 13 to 15 amendments of the US Constitution called the Civil War amendments?

The Thirteenth, Fourteenth, and Fifteenth Amendments are known as the Civil War Amendments or as some historians call them, the Reconstruction Amendments. These three amendments specifically addressed equality and fundamental civil rights for freed slaves. Although they target free slaves, as with all of the amendments, all United States citizens benefit from the protection these amendments provide.
By war's end, it was estimated there were approximately four million men, women, and children who would no longer be slaves. Assimilation into civil society would prove to be difficult as the former slave states resisted every effort to accept defeat and the new found freedom of the former slaves. The newly emancipated African Americans faced an uncertain future because though slavery was no longer legal and permitted in the United States, the former slave states continued to find ways to circumvent the laws. Congress, the Senate, and the President were forced to exert federal authority in the matter of protecting these new citizens from former slave states imposing regulations that kept them from enjoying the same freedoms and rights as other citizens. The end of the real war signaled the beginning of an ideological battle and a refusal by states to recognize freed slaves as citizens.
The Constitution in Amendments Thirteen through Fifteen are known as the Civil War Amendments or the Reconstruction Amendments because they addressed the ideological war waged against the civil rights of freed slaves.
https://www.blackpast.org/african-american-history/reconstruction-amendments/

https://www.pbs.org/tpt/slavery-by-another-name/themes/reconstruction-amendments/