What migrant group dominated urban labor in latin america during much of the 19th century?

The bulk of the immigrants that came to Latin America during the 19th Century came from Spain, Italy, France, Russia, Germany, Switzerland and Britain.  They came because during this time leaders in Latin America wanted to modernize their economy by bringing in new technology and attract investments from foreigners.  Part of their plan was to attract foreigners to work on their lands and even invited them to settle there.  A good example of this was in Argentina where many Europeans came to work as some stayed while others were seasonal employees.

the technology changed agriculture in an impacting manner since many people left the field work by a cellular or other technological appliances