From the time the Portuguese first arrived until slavery was outlawed in the New World, there existed a West African slave trade. Before 1492, the Portuguese began importing slaves from Africa. The demand for slaves and the slave trade skyrocketed after 1492. Brazil did not abolitionize slavery until 1888. Even when the slave trade was outlawed in country after country, some slave traffickers continued to operate in violation of the law in order to profit.
The transatlantic slave trade can also be understood through its sheer magnitude: for 366 years, European slavers loaded approximately 12.5 million Africans onto Atlantic slave ships. About 11 million survived the Middle Passage to landfall and life in the Americas.
The North's goal was to invade the South to try to subdue their desire to secede, while the South's strategy was to defend their territory until the North gave up.
Honestly, I tried to look but I don't know. Here's a picture of the general area that it should be around (the red box). This is in Italy north of Rome.