A great question, and one that could be discussed for hours!  One main reason that immigrants were brought to Ellis Island was that immigrants coming to the U.S. were not screened by their countries of origin.  At the time of the island's opening as an immigration station, immigrants were facing stricter laws to enter this country, and we were in the midst of a cholera scare.  

The Island remained throughout the turn of the century as a means to better document and screen individuals and families entering the U.S. through the port of New York.  

This changed in World War I, when most countries closed their borders, and the oceans became too dangerous to travel.  

To learn more, please visit our page on Ellis Island here.