Answer:
1. Immigration from 1901 to 1910 had a greater impact on the US than immigration from from 2001-2010 because immigration laws were a lot less strict before the events of 9/11 therefore more dangerous and unchecked people were allowed to ener the US in large numbers while after the events of 9/11 immigration laws began to change calling for stricter actions and less danger toward the US.
2. The large drop seen in the graph betwwen 1930-1950 is from the events of the great depression where the US is struggling therefore it cannot afford to have more immigrants eneter the US, and not many wanted to enter anyways from its lack of economical benefits at the time.
3.Between 1890 and 1920, we can estimate that around 20,000,000 immigrants immigrated to the US based on the graph.
