Here's a good listen (or read) from NPR on the worldwide slave trade
that still plagues us humans. While it is mentioned that there are more slaves in the world today than at any time in our history, this is probably statistical double-speak, since there are more humans in the world today than ever before - I doubt the percentage of slaves now is higher than ever before. The more depressing point from Benjamin Skinner, a New York Journalist:
"In 1850, a slave would cost roughly $30,000 to $40,000 — in other words it was like investing in a Mercedes. Today you can go to Haiti and buy a 9-year-old girl to use as a sexual and domestic slave for $50. The devaluation of human life is incredibly pronounced."