Well, vaguely revisionist history aside, that was at least part of what the civil war was over. The southern states were upset that the constitution in the case of slavery could override their state powers and ban slavery. The confederate states wanted to rewrite the constitution to strip the federal government of essentially all powers except the power to wage war and the regulation of interstate commerce, essentially blocking it from having any impact on the activities wholly within a state. The Union states of course wanted to keep the constitution as it was (or even strengthen it), that is giving the federal government veto power over states and the ability to enforce human rights guaranteed by the constitution. Thus in one sense the civil war was a fight over a weak vs. strong federal government. When making that argument though it's important not to downplay the importance of slavery as a motivating factor for the confederate states. Many revisionist white supremacists try to make that argument as a way of whitewashing the confederate states actions and trying to re-frame the confederate states motivations as being non-racist, when they were anything but.
Don't believe everything everyone says about themselves.