The Black Sea was the waterway most controlled by the Byzantine Empire during its height and most of its existence. Constantinople which is nowadays know as Istanbul was the capital city of the empire and it was located in the Bosphorus strait, which is the connecting link between Mediterranean Sea and the Black sea.
That geographical area was a strategic point for commercial routes between Europe and Asia, and it was also military disputed due to be considered the entrance to Europe for eastern invaders.
At its height, the Byzantine Empire controlled most of the Black Sea. The capital of the empire , Constantinople, was located at the Black Sea and the Bosporus. The Bosporus connected the Black Sea and the Mediterranean Sea. The Byzantine Navy was under the rule of Justinian I, who ruled for nearly 40 years from 527 till 565, the master in the Mediterranean Sea. Constantinople was because of the central location very popular for traders from Asia and Europe.
The name given to the loose organization of people dedicated to helping escaped slaves get to free territory was the "Under Ground Railroad." Hope this answer helped!
Life was hard because many southern cities lay in ruins and there where
no jobs around leaving Africans Americans homeless and penniless. Hope this helps