The Native Americans. But what the history books want you to believe is that it was Christopher Columbus.
-TTL
Push factors include war, famine, descrimination ect. in the native country of the migrant eg Irish people were pushed to emigrate to america and england during the Great Hunger (1845-1849)
pull factors include the promise of good job opportunities in america, hot climate, ect
Umm in 1911 the last dynasty the Qing (Ching) became the republic of China