The Atlantic slave trade was one of the worst events in human history. Slavers forced millions of people to leave their homes in Africa in order to grow crops in plantations all over America. This video gives a short summary of what happened.
The video has subtitles in English, Spanish and other languages if you want to use them.
There are also some comprehension questions and extra information if you follow this link http://ed.ted.com/on/eeqMBUov#review