No it wasn't. Not even in the slightest.
First, there is no such thing as "states' rights." States are governments and governments do not have rights - people do.
Second, even if states had any of these imaginary rights, the federal government had done absolutely nothing to violate these pretended rights in any way before the seceding states seceded.
The whole concept of "states' rights" is an invention cooked up to preserve slavery.
If it weren't, defenders of the Confederacy would be able to itemize these alleged offenses against "states' rights" - but they never can.
The powers not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.
Semantics.
The whole concept of "states' rights" is an invention cooked up to preserve slavery.
So the 10A doesn't exist?
If it weren't, defenders of the Confederacy would be able to itemize these alleged offenses against "states' rights" - but they never can.