The Union wasn't fighting for more powers for the federal government, just for the integrity of the existing federal government and it's powers.
The war resulted in some expansion of federal power, but that wasn't what motivated the Union.
The Union wasn't (particularly the slave states in the Union weren't) fighting to abolish slavery, the Union wasn't fighting to preserve the Union, a goal to which the popular (in most of the North) cause of abolition had been deliberately subordinated in the elections prior to the war.
OTOH, by seceding, the rebel states also lost their leverage on preserving slavery within the Union, so the whole rebellion backfired. Abolition probably would have happened eventually without the war, but it wouldn't have been right away.
Small countries don't have much leverage on their own on the world stage. CA and NY are almost certainly better off as part of the greater whole.
Often it's the other way around - for example, in the pre-Civil War era, a big point of contention (that was specifically cited later by those states that tried to secede) was that the federal government enacted the Fugitive Slave Act of 1850, which forced the free states to, basically, participate in enforcement of slavery on behalf of the slave states.
The federal government doesn't seem concerned that the state I live in requires you to pay about $200 and get the local chief of police to sign off before you can exercise a particular right in any capacity whatsoever.
Civil asset forfeiture is still a thing in many states.
Some state could adopt an obviously unconstitutional hate speech law tomorrow and it would take years before it's struck down and even then there'd be no recourse for those already punished under it. If the state continued to enforce the law then what would happen? After another year or three of hearings and court whatnot they'd get cut off from some funding or something.
The best you can hope for when your state is violating your rights is a supreme court ruling that makes your state go "aw shucks boys, guess we can't do that anymore" and that your state actually does stop doing it. I don't see a weaker federal government changing that status quo.
The danger of putting all your eggs in the federal basket is that when something dumb happens on that level it affects us all (e.g. the net neutrality debacle). At least with the states the stupidity has to happen on it's own in each state.
It’s far from perfect. States still try to violate civil rights and it still takes a long time to fix that, if ever. The feds sometimes push more restrictions against the wishes of states that want more freedom, like with marijuana. But overall, based on history, I think that giving the states more freedom would be a huge step backwards.
This is been tried already, and it didn’t work. What changed things was force, first military, then legal.
There's a huge culture problem in the US.
https://www.usnews.com/news/articles/2016-05-17/after-brown-...
Schools are still segregated. We're still enslaving people in prisons.
Sure. There aren't LAWS that say segregation MUST exist. That's a step in the right direction, I suppose...