Answer:
<h2>The answer is explained below </h2>
Explanation:
A fall line is an area where a coastal plain and upland region meet and prominent rivers cross it that results in waterfalls.
The coastal plain is made of softer sedimentary rock while uplands are crystalline basement rock. In US fall line is a 1,400 kilometres escarpment line where the Atlantic Coastal plain and Piedmont meet
The Eastern seaboards fall line was important for the economic development of the US because the elevation change along fall line allowed the settlers to use the water as a source of energy. The mills also used machinery which was powered by water.
Pennsylvania, Philadelphia, Virginia, Richmond, New Jersey and Trenton were the cities that developed along the fault line. .
