The Allies gained control of the Atlantic Ocean by learning from the past and improving technology, strategies, weapons. Allies started to build large number of ships. Also people sacrificed themselves to take supplies from Canada and US to the UK. Allies developed anti-submarines weapons. Also a special group of destroyers were developed in order to set the location of U-boats.
First Continental Congress, I believe
At the peak of the Roman Empire's reach, around A.D. 117, the Empire stretched as far north as modern Scotland, stretched down through Europe east into Asia as far as the border between modern day Iraq and Iran, with its southern reaches extending into northern Africa.
