Eastern boundary currents are associated with the cooling off of the ocean waters. These currents originate from both of the poles, they bring cold, shallow, slow water towards the lower latitudes and cools of the water near the Equator. Once there they are warming up and move in the opposite direction as westward warm currents.
A fall line is an upland region of the coastal plains meets and the term states that lots of rivers fall from this Piedmont to the coastal plain making rapids with waterfalls.
These falls are important as for the settlement as they block the ocean going ships from entering in any further upstream and also provided water power to run the region industries.