Aminimum of african captives were transported to the americas during the trans-atlantic slave trade.

According to the Trans-Atlantic Slave Trade Database, that there are over 10 million Africans for transference to the Americas between the sixteenth and nineteenth centuries. Slaves were kept in a factory while in anticipation of shipment. Current estimates are that about 12 million Africans were sent across the Atlantic, although the number acquired by the traders was significantly higher, as the route had a high death rate. Near the beginning of the 19th century, numerous governments acted to veto the trade, though illegal smuggling still happened. 

travels along an axon. this triggers a wave of electrical activity that passes from the cell body along the length of the axon to the synapse