The ku klux klan rose up and started killing minorities and spreading terror within the southern and "south"-northern states
I’m pretty sure that the answer is a
Constitutional Convention! A Constitutional Convention is a gathering with a purpose or writing a new constitution or revising an already existing one.
I am not so sure what you mean by "what kinds of unions were formed", but if you're talking about the Civil War then I think the unions were Confederate and Union. The Confederates wanted to run the country with slavery while the Union fought against slavery. Do not quote me on that though.
