I only remember that they were dragged over here on ships, in the worst possible conditions. I took Global History from 1999 - 2001. My memory is also mostly selective :/
They were brought over in ships in horrible conditions. However, the question is "how did they get on the ships?". The slavers would put into Africa, and buy the slaves from other Africans. The slaves could be members of a captured rival tribe, or simply members of the chief's own tribe who were considered extraneous persons. Some chiefs even sold their own offspring to the slavers. The trade was very uneven, with the africans receiving old military uniforms, beads and other assorted cheap trinkets in return for human beings.