"The heavy tectonic activity in the area" had the greatest impact on South America's physical geography. This is true because the heavy activity of the tectonic in the area such as plate motions resulted in the formation of mountains and oceans in South America.
For example, the formation of the massive Andes Mountains and the formation of various volcanoes resulted from heavy activity of the tectonic in the area.
Immigration Reform and Control Act or better known as the
IRCA was passed in order to amend, reform, and revise the Immigration and
Nationality Act which barred immigration into the United States. This Act was
also to control illegal immigration into the United States.
