What do you think finally led some people to try to abolish slavery

I believe, the change in perspective actually led those people to try and abolish slavery.
Back then, most people believe that nothing wrong with slavery and view it as something normal that just happen in society. (which is also essential for plantation's operation)
But overtime, they started to see how the slaves were suffering and struggling for their freedom to the point that they started to understand the slaves' feeling and willing to join the fight for their freedom.

Yes, they are always very triggered