West African slavery lives on, 400 years after trans-Atlantic trade began

Currently: Over 40 million people are estimated to be trapped in forced labor. Africa has the highest prevalence of slavery, with more than seven victims for every 1,000 people. Currently !!!!! Slavery was in practice before the "trans-Atlantic trade began" and it still continues to this day. America outlawed Slavery.
When will the rest of the world catch up??