What were convoys used for?

The primary purpose of convoys in WWI was to protect cargo ships and unarmed troop transports from submarine attacks.

Just think, why was it effective? -it appeled to critics because it was written well, that made it noticeable to the public including the white population-it was also recognizable to the african americans because it was about their heritage.-it was powerful just keep finding more points and elaborate on them. message me if you need more