The most inhumane aspect of the triangular trade was where?

In terms of the part of the trade that would be the part where the slaves were captured (or bought) in Africa and brought to America - the rest of the trade included goods, not people.

Some of the slaves had an acceptable (not good: acceptable) life in America, so i would say that on a smaller scale, the being on the ship was even more inhumane: they were in chains the whole journey and many, many died on the ships.