The immigration from 1901 to 1910 had a greater effect on the USA than the immigration from 2001 to 2010.
This statement is true because the USA's foreign-born population is 50 million or 14 % of the total US population of 312 million according to the 2011 American Community Survey.
By 1910the immigrant share of the population peaked at 15 %. The foreign share of the population fell to 5% in 1970 and by 2010 it was around 6 %.