What three developments do you think has had the greatest global effect

Developments in what aspect? For the purpose of this discussion we will focus on the recent important human technological advancement.1) Industrial revolution is one of the influential development of man2) Computer age is another massive leap for man3) Primitive but rather recent, scientific revolution.We appreciate your questions. Please, never hesitate to ask more in your queries. 

Be the economy is horrible so people immigrate to the usa for a better life. most people just grow up from poverty and work day and night to support their family, some just come because there is a lot of drug dealers and gang that assaults people.