Middle Passage
Enslaved people were treated so badly on the slave ships that about 15% of them died during the Middle Passage.  Even more were killed before they left Africa, when slave traders were trying to kidnap them and force them onto the slave ships.  Historians think that up to two million African people died during the Middle Passage. However, somewhere between 9.4 million and 12 million African people survived the Middle Passage, and arrived in the Americas as slaves.