re: True or False...the civil war was fought over slavery.

True. It's couched in terms of state's rights etc. but it's really about slavery and how the South was heavily reliant on slave labor for their economy.

Also the growing fear that when free states outnumbered slave states that slavery would be eventually abolished.

Can got kicked down the road several times... Missouri compromise, compromise of 1850, etc.

So the rich plantation owners with political power in the South saw the writing on the wall and attempted to secede.

It's not all about slavery, but slavery was the main overriding issue, more specifically the continuation of slavery.