C. They founded a secret society known as the KKK .
Step-by-step explanation:
The white Southerners who opposed the principles that were in the Louisiana Constitution of 1868 founded the Klu Klux Klan.
The Louisiana Constitution of 1868 gave a lot more rights to black citizens, this angered a lot of white citizens and caused a lot of disagreement. White Southerners created the Klu Klux Klan, which held a hatred for African Americans and wanted to destroy their rights. This caused many African Americans to be unfortunately murdered and many massacres occurred during this time.