This is the one weird trick that museums use to pull in donor dollars.

Look around Wikipedia, you find a little more info re slavery and this ship. Kansas and Missouri were on the violent border with a mixture of pro and anti-slavery views, even as the geographical boundary of allowed slavery separated "the south". The museum website says there's clothing on the ship that has a pro-slavery mark, to be sent to some store. The ship at one time was boarded by pro-slavery forces who found hidden guns that were being shipped to abolitionists. It does not appear they sent slaves on it en mass.

There were plenty of people who were pro slavery in those days. Mixed all across the US, read Mark Twain. There were plenty of people against it.

More to the point, I wonder if the museum addresses this. I'm going to guess only in a small way, having lived half my life in the south. Maybe someone with actual knowlege can comment instead of web search "experts" like me.