Yes, slavery has been a global issue and all racial types have been enslaved, whites, blacks, jews. Blacks also enslaved other blacks.
In America, blacks were enslaved and groups of Southern white people did this. It truly was terrible. Read the bio by Frederick Douglas on this.
But yes, a large group of whites tried to stop slavery. They were the good guys. And some guys like John Brown who wasn't really good, but fought for a good cause. He would butcher slave owners at night while they slept in their tents.
The conclusion that we can draw is that we have good and bad in all racial groups and as humans we need to strive for the good, reject the bad, and reject focusing on skin color and stereotypes.