@aral

My pet project, given a time machine, would be to stop slavery from ever starting up in the U.S.A.

A) I assume I've got infinite funds, because hey, time machine.
B) I understand naval logistics to a small degree, based on experience.
C) I'd be able to change my plans as slavers true to change theirs.

How do? Mine the slaver lanes with lots of explosives, constantly. Any that got missed, could be taken care of retroactively.

D) Explosions are cool. 😁

A general approach to the question of "Why....?" regarding human behavior is "Because $$$." So, if you make it too expensive to run a slave trade because all your ships heading East become toothpicks, captains sometimes survive telling ghost stories of people appearing out of thin air and causing havoc before the ship became toothpicks. After a while, people aren't going to invest money in making slavery profitable.

Also deal with anyone who decides to switch to indentures.

What this does, going forward, I'm not smart enough to say. Is agriculture in the South profitable enough that landowners would still invest in and be able to produce large amounts of goods at a profit if they have to pay their workers? Dunno.

U.S. slavery gave us the Senate and the civil war. Jim Crow laws gave Hitler ideas. Underlying it for me though is that people shouldn't own people.

Colonialism is a much bigger picture that I don't have enough of an understanding, big picture wise, that I'd feel comfortable taking on by my lonesome.