I’m a little late to the game in discovering this great post on Slate. This is a powerful depiction of the Atlantic slave trade. Watch how many ships end up either in Brazil or Saint Domingue. Clicking on an individual ship also helps you get a sense of the tremendous loss of lives during each journey.

http://www.slate.com/articles/life/the_history_of_american_slavery/2015/06/animated_interactive_of_the_history_of_the_atlantic_slave_trade.html?wpsrc=sh_all_tab_tw_top